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Cellulose from lignocellulosic biomass (LB) is of increasing interest for the production of commodity chemicals. However, its use as substrate for fermentations is a challenge due to its structural complexity. In this context, the highly cellulolytic Clostridium cellulovorans has been considered an interesting microorganism for the breakdown of LB. C. cellulovorans does not naturally produce solvents in useful concentrations, but this could be achieved by metabolic engineering. Unfortunately, this is hampered by the lack of tools for genetic engineering. We describe a genetic system that allows strain engineering by the allelic-coupled exchange method. First, the Gram-positive origin of pUB110 was identified as a suitable clostridial 'pseudo-suicide' origin of replication for the construction of deletion vectors. Second, an efficient counterselection strategy based on a codBA cassette and the use of 5-fluorocytosine as the counterselective compound was employed. Third, since the prevention of DNA transfer by host restriction-modification (RM) systems is a critical barrier to genome engineering, deletion plasmids containing flanking regions for the putative type I (Clocel_1114) and III (Clocel_2651) RM systems were constructed and transferred into C. cellulovorans. The restriction-less strains C. cellulovorans ΔClocel_1114 and C. cellulovorans ΔClocel_2651 exhibit high conjugation efficiency and can be easily used for further metabolic engineering. • A new gene editing system was developed for the highly cellulolytic bacterium Clostridium cellulovorans. • C. cellulovorans has several strong restriction-modification (RM) systems that impair metabolic engineering approaches. • The newly developed gene editing system enabled the knockout of the putative type I and type III RM systems. • The C. cellulovorans strains generated in this work can be used as chassis for the biotechnological production of valuable lignocellulosic chemicals and biofuels. [ABSTRACT FROM AUTHOR]

Simple Summary: Mexico ranked among the ten countries with the highest GHG production in 2017, reporting a contribution of 1.68% of global emissions; in this sense, it has committed to reducing GHG emissions by up to 22% by 2030 (Government of Mexico, 2015). The First National Tier 2 Inventory of methane emissions from enteric fermentation of cattle in Mexico, registering 2039.21 ± 205.5 Gg of CH4 per year. Currently, most studies on livestock and climate change in Latin America are focused on quantifying CH4 emission volumes, determining emission factors, and calculating national inventories; few studies focus on the development of mitigation strategies; many positive attributes of macroalgae have been identified concerning contributing nutrients such as protein and also in the energy metabolism of animals of livestock interest. Some in vitro studies have shown that red and brown macroalgae can reduce CH4 production by controlling the populations of methanogenic bacteria in the rumen. The impact of macroalgae species on rumen function remains largely unexplored. This present study aimed to identify the biocompounds of the three types of marine macroalgae described: Macrocystis pyrifera (Brown), Ulva spp. (Lettuce), Mazzaella spp. (Red) and their effect on species-specific modulations of the rumen microbiome. The macroalgae were characterized using GC-MS. Twelve Rambouillet lambs were randomly assigned to one of four experimental diets (n = 3 per treatment): (a) control diet (CD); (b) CD + 5 g of Red algae; (c) CD + 5 g of Brown algae; and (d) CD + 5 g of Lettuce algae. After the lambs ended their fattening phase, they donated ruminal fluid for DNA extraction and 16S rRNA gene V3 amplicon sequencing. Results: The tagged 16S rRNA amplicon sequencing and statistical analysis revealed that the dominant ruminal bacteria shared by all four sample groups belonged to phyla Firmicutes and Bacteroidota. However, the relative abundance of these bacterial groups was markedly affected by diet composition. In animals fed with macroalgae, the fibrinolytic and cellulolytic bacteria Selenomonas was found in the highest abundance. The diversity in chemical composition among macroalgae species introduces a range of bioactive compounds, particularly VOCs like anethole, beta-himachalene, and 4-ethylphenol, which demonstrate antimicrobial and fermentation-modulating properties. [ABSTRACT FROM AUTHOR]

Introduction: Several species of cellulolytic bacteria display cellulosomes, massive multi-cellulase containing complexes that degrade lignocellulosic plant biomass (LCB). A greater understanding of cellulosome structure and enzyme content could facilitate the development of new microbial-based methods to produce renewable chemicals and materials. Methods: To identify novel cellulosome-displaying microbes we searched 305,693 sequenced bacterial genomes for genes encoding cellulosome proteins; dockerin-fused glycohydrolases (DocGHs) and cohesin domain containing scaffoldins. Results and discussion: This analysis identified 33 bacterial species with the genomic capacity to produce cellulosomes, including 10 species not previously reported to produce these complexes, such as Acetivibrio mesophilus. Cellulosome-producing bacteria primarily originate from the Acetivibrio, Ruminococcus, Ruminiclostridium , and Clostridium genera. A rigorous analysis of their enzyme, scaffoldin, dockerin, and cohesin content reveals phylogenetically conserved features. Based on the presence of a high number of genes encoding both scaffoldins and dockerin-fused GHs, the cellulosomes in Acetivibrio and Ruminococcus bacteria possess complex architectures that are populated with a large number of distinct LCB degrading GH enzymes. Their complex cellulosomes are distinguishable by their mechanism of attachment to the cell wall, the structures of their primary scaffoldins, and by how they are transcriptionally regulated. In contrast, bacteria in the Ruminiclostridium and Clostridium genera produce 'simple' cellulosomes that are constructed from only a few types of scaffoldins that based on their distinct complement of GH enzymes are predicted to exhibit high and low cellulolytic activity, respectively. Collectively, the results of this study reveal conserved and divergent architectural features in bacterial cellulosomes that could be useful in guiding ongoing efforts to harness their cellulolytic activities for bio-based chemical and materials production. [ABSTRACT FROM AUTHOR]

Black soldier fly larvae (BSFL) have attracted attention due to their ability to upcycle various biological side streams into valuable biomass, such as proteins, lipids, and chitin. In this study, we investigated the impact of high-fiber diets on larval growth performance and the shift of microbes in the gut. We tested empty fruit bunches (EFB), potato pulp (PP), and cottonseed press cake (CPC), with chicken feed (CF) used as a control diet. We found that larvae reared on the EFB, PP, and CPC were smaller than control larvae at the end of development due to the low nutritional value of the diets. However, survival rates of more than 90% were observed regardless of the diet. We used a cultivation-dependent approach to analyze the microbial community in the gut of BSFL, isolated, and identified a total of 329 bacterial strains. Bacillaceae were most frequently isolated from larvae reared on the high-fiber EFB diet. These isolates were predicted to degrade cellulose in silico and this was subsequently confirmed in vitro using the Congo Red assay. Whereas the members of Enterobacteriaceae and Morganellaceae were mostly found in guts of larvae reared on the high-protein diets CPC and CF. We conclude that the gut microbiome plays a crucial role in the digestion of fiber-rich plant organic material, thereby enabling the BSFL to successfully complete their life cycle also on substrates with low nutritional value. As a result, BSFL convert industrial side streams into valuable biomass, reducing waste and promoting sustainability. IMPORTANCE Organic side streams from various industries pose a challenge to the environment. They are often present in huge amounts and are mostly discarded, incinerated, used for biogas production, or as feed for ruminant animals. Many plantbased side streams contain difficult-to-digest fiber as well as anti-nutritional or even insecticidal compounds that could harm the animals. These challenges can be addressed using black soldier fly larvae, which are known to degrade various organic substrates and convert them into valuable biomass. This will help mitigate agro-industrial side streams via efficient waste management and will contribute to the more economical and sustainable farming of insects. [ABSTRACT FROM AUTHOR]

Cellulase enzymes are widely used in the food, beverage, animal feed, textile, and paper industries. The high cost of producing enzymes and low enzyme activity provides opportunities for using chemicals, and efforts are needed to produce cellulase enzymes economically through media optimization. This research aims to find alternative media that make it possible to produce cellulase enzymes with high activity. This research created a control media (M0) using pro-analysis chemicals and CMC as a carbon source. Three types of cellulolytic bacterial growth media were also created, consisting of technical chemicals, rice straw as a substrate, and different protein sources. M1: alternative media using urea as a protein source; M2: alternative media using powdered milk as a protein source; and M3: alternative media using chicken liver as a protein source. A total of 1% of cellulolytic bacteria (Actinobacillus sp.) was grown in each media and then incubated at 40°C for 33 hours at a speed of 140 rpm, and the production curve and cellulase enzyme activity were measured at every 3-hour interval. The results showed that the highest cellulase enzyme production was achieved at 24 hours using alternative media with powdered milk (M2) as a protein source. The cellulase enzyme activity produced was 2.9612 µ/ml.

The objective was to assess the supplementation with microencapsulation of hemp leaf extract (mHLE) utilized as a rumen enhancer on in vitro rumen fermentation and to enhance the bioavailability of active compounds for antimicrobial action, particularly in protozoa and methanogen populations. The feed treatments were totally randomized in the experimental design, with different levels of mHLE diet supplemented at 0, 4, 6 and 8% of total DM substrate and added to an R:C ratio of 60:40. During fermentation, gas kinetics production, nutrient degradability, ammonia nitrogen concentration, volatile fatty acid (VFA) profiles, methane production, and the microbial population were measured. The supplemented treatment at 6% of total DM substrate affected reductions in gas kinetics, cumulative gas production, and volatile fatty acid profiles, especially the acetate and acetate to propionate ratio. Whereas propionate proportion and total volatile fatty acid concentration were enhanced depending on the increase of nutrients in vitro dry matter degradability (IVDMD) after 12 h of post-fermentation at a R:C ratio of 60:40 (P < 0.05). Consequently, mHLE addition resulted in optimal ruminal pH and increased nutrient degradability, followed by ammonia nitrogen concentrations (P < 0.05), which were enhanced by dominant cellulolytic bacteria, particularly Ruminococcus albus and Ruminococcus flavefaciens, which showed the highest growth rates in the rumen ecology. Therefore, mHLE, a rich phytonutrient feed additive, affected the methanogen population, reduced the calculated methane production and can be a potential supplement in the ruminant diet. [ABSTRACT FROM AUTHOR]

Renewable alternatives for nonelectrifiable fossil-derived chemicals are needed and plant matter, the most abundant biomass on Earth, provide an ideal feedstock. However, the heterogeneous polymeric composition of lignocellulose makes conversion difficult. Lignin presents a formidable barrier to fermentation of nonpretreated biomass. Extensive chemical and enzymatic treatments can liberate fermentable carbohydrates from plant biomass, but microbial routes offer many advantages, including concomitant conversion to industrial chemicals. Here, testing of lignin content of nonpretreated biomass using the cellulolytic thermophilic bacterium, Anaerocellum bescii, revealed that the primary microbial degradation barrier relates to methoxy substitutions in lignin. This contrasts with optimal lignin composition for chemical pretreatment that favors high S/G ratio and low H lignin. Genetically modified poplar trees with diverse lignin compositions confirm these findings. In addition, poplar trees with low methoxy content achieve industrially relevant levels of microbial solubilization without any pretreatments and with no impact on tree fitness in greenhouse. [ABSTRACT FROM AUTHOR]

The aim of this work was to reduce the postweaning stress of growing rabbits by using fasting regimen and probiotic supplementation. Twenty‐four weaned males new Zealand rabbits (5 weeks of age) were randomly divided into four equal groups including (1) rabbits fed ad labium diet served as control, (2) rabbits fasted for 12 h (two days/week) for 8 weeks, (3) rabbits fed ad labium diet with 2.0 cm3 probiotic/litter for 8 weeks, (4) rabbits fasted for 12 h (2 days/week) and take 2.0 cm3 probiotic/litter for 8 weeks. The probiotic inclusion corresponded to Bacillus subtilis and Bacillus licheniformis were supplemented to water in the probiotic groups. Results showed that food consumption was significantly higher (p < 0.01) in growing rabbits of ad libitum group (control group) compared to other in restricted rabbits, but body weight (BW) of growing rabbit in probiotic group at 6 and 12 week of age increased by12 and 19%, respectively, than other in control group and also improved daily weight gain (DWG) during all experimental periods. Compared with control, significant reductions (p <.01) in Plasma cholesterol, triglycerides, HDL, LDL, ALT, AST and urea were found in oral probiotic groups with or without fasting programme. Oral administration of probiotic without fasting regimen significantly improved all carcass characteristics compared to other groups. Total bacteria, fungi, coliforms and cellulolytic bacteria counts were significantly improved in the fasting group with or without adding probiotics compared to control group. Conclusively, using probiotics with or without fasting regimen for 8 weeks postweaning improved growth performance during fattening and enhancement cecum activity of growing rabbits. [ABSTRACT FROM AUTHOR]

Raw potato fries are a type of potato by-product (PBP), and they have great potential as a partial replacement of grain in animal feeds to improve the environmental sustainability of food production. This study aimed to investigate the effects of replacing corn with different levels of PBP (0%, 12.84%, 25.65%, and 38.44%) in the total mixed ration (TMR) of Angus bull. Sixty 16-month-old Angus bulls (548.5 ± 15.0 kg, mean ± SD) were randomly assigned to four treatments. The results indicated that with the increase in the substitution amount of PBP, the body weight decreased significantly. The dry matter apparent digestibility and starch apparent digestibility linearly decreased as PBP replacement increased. The feed ingredient composition in the TMR varied, leading to a corresponding change in the rumen microbiota, especially in cellulolytic bacteria and amylolytic bacteria. The abundance of Succiniclasticum in the 12.84% PBP and 38.44% PBP diets was significantly higher than that in the 0% PBP and 25.65% PBP diets. The abundance of Ruminococcus linearly increased. In conclusion, using PBP to replace corn for beef cattle had no negative impact on rumen fermentation, and the decrease in apparent digestibility explained the change in growth performance. Its application in practical production is highly cost-effective and a strategy to reduce food waste. [ABSTRACT FROM AUTHOR]

Background: Compost-bedded pack barns (CBP) are getting huge attention as an alternative housing system for dairy cows due to their beneficial impact on animal welfare. Effective microorganisms (EM) inoculums are believed to enhance compost quality, improve soil structure and benefit the environment. However, little information is available on the impact of incubation with external EM combinations on the barn environment, compost quality and microbial diversity in CBP. This experiment was carried out to investigate the effect of inoculating different combinations of EM [Lactobacillus plantarum (L), Compound Bacillus (B) and Saccharomyces cerevisiae (S)] on compost quality and microbial communities of CBP products, as well as the relationship with the heifers' barn environment. CBP barns were subjected to the following four treatments: CON with no EM inoculum, LB/LS/LBS were Incubated with weight ratios of 1:2 (L: B), 1:2 (L: S), 1:1:1 (L: B: S), respectively. Results: The EM inoculation (LB, LS, LBS) reduced the concentration of respirable particulate matter (PM10 and PM2.5) in the CBP, and decreased the serum total protein and total cholesterol levels in heifers. Notably, LBS achieved the highest content of high-density lipoprotein compared to other treatments. Microbiome results revealed that EM inoculation reduced the bacterial abundance (Chao1 index) and fungal diversity (Shannon & Simpson indexes), while increasing the relative abundance of various bacterial genera (Pseudomonas, Paracoccus, Aequorivita) and fungi (Pestalotiopsis), which are associated with cellulose decomposition that ultimately resulted in accelerating organic matter degradation and humification. Furthermore, high nutrient elements (TK&TP) and low mycotoxin content were obtained with EM inoculation, with LBS showing a particularly pronounced effect. Meanwhile, LBS contributed to a decline in the proportion of fungal pathogen categories but also led to an increase in fungal saprotroph categories. Conclusion: Generally, EM inoculation positively impacted compost product quality as organic fertilizer and barn environment by modifying the abundance of cellulolytic bacteria and fungi, while inhibiting the reproduction of pathogenic microbes, especially co-supplementing with L, B and S achieved an amplifying effect. [ABSTRACT FROM AUTHOR]

The present experiment was conducted at Department of Plant Pathology, College of Agriculture, Navsari Agricultural University, WaghaiduringMarch-October, 2021. cellulolytic bacterial isolates CD11, CD17, CD19, CD22 and CD35 were screened to determine the staining efficiency of various stains for cellulase activity on CMC (Carboxy Methyl Cellulose) agar and it was observed that all the isolates conferred clear zone around the colonies through different staining dyes and bacterial isolate CD35 showed the highest cellulolytic index in all the dyes. The cellulolytic index of CD35 was highest with gram's iodine (3.34) next in order of coomassie brilliant blue (2.96), safranin (2.55) and congo red (2.15). Significantly, higher cellulase activity was recorded in CD35 (0.169 U ml-1) at 24 hrs after inoculation It was followed by CD17 (0.124 U ml-1), CD19 (0.101 U ml-1) and CD11 (0.081 U ml-1), while it was lowest in CD22 (0.052 U ml-1). Maximum cellulase activity was recorded at 72 hrs after inoculation by all the selected isolates except CD22 isolate, which was maximum 96 hrs after inoculation. CD35 gave significantly maximum cellulase activity (0.822 U ml-1) at 72 hrs after inoculation. Next in order to cellulase activity was CD17 (0.477 U ml-1) which was at par with CD19 (0.471 U ml-1) followed by CD11 (0.292 U ml-1) while, it was lowest in CD22 (0.199 U ml-1). Cellulolytic bacteria CD35 was identified as Bacillus subtilis by morphological, biochemical and molecular methods and submitted to NCBI GenBank database with accession numbers MW715021. [ABSTRACT FROM AUTHOR]

Despite their low quantity and abundance, the cellulolytic bacteria that inhabit the equine large intestine are vital to their host, as they enable the crucial use of forage-based diets. Fibrobacter succinogenes is one of the most important intestinal cellulolytic bacteria. In this study, Fibrobacter sp. HC4, one cellulolytic strain newly isolated from the horse cecum, was characterized for its ability to utilize plant cell wall fibers. Fibrobacter sp. HC4 consumed only cellulose, cellobiose, and glucose and produced succinate and acetate in equal amounts. Among genes coding for CAZymes, 26% of the detected glycoside hydrolases (GHs) were involved in cellulolysis. These cellulases belong to the GH5, GH8, GH9, GH44, GH45, and GH51 families. Both carboxymethyl cellulase and xylanase activities of Fibrobacter sp. HC4 were detected using the Congo red method and were higher than those of F. succinogenes S85, the type strain. The in vitro addition of Fibrobacter sp. HC4 to a fecal microbial ecosystem of horses with large intestinal acidosis significantly enhanced fibrolytic activity as measured by the increase in gas and volatile fatty acids production during the first 48 h. According to this, the pH decreased and the disappearance of dry matter increased at a faster rate with Fibrobacter sp. HC4. Our data suggest a high specialization of the new strain in cellulose degradation. Such a strain could be of interest for future exploitation of its probiotic potential, which needs to be further determined by in vivo studies. [ABSTRACT FROM AUTHOR]

Cellulolytic bacterial play an important role in the synthesis of microbial protein in the small intestine as high-quality protein. This research aimed to observe the growth patterns of cellulolytic bacterial isolates from the feces of endemic herbivorous animals in Indonesia, and to evaluate the effect of the addition of cellulolytic bacterial isolates on the synthesis of microbial proteins in vitro. The study used a completely randomized design with four treatments and five replications. The treatments included T0 = Concentrate mix 40%: elephant grass 30%: palm leaves 30% (control), T1 = T0 + 105 CFU mL-1 cellulolytic bacterial isolate, T2 = T0 + 106 CFU mL-1 cellulolytic bacterial isolate, and T3 = T0 + 107 CFU mL-1 cellulolytic bacterial isolate. Variables measured were the growth pattern of bacterial isolates, bacterial population at the optimal growth point, and microbial protein synthesis. The results showed growth pattern of cellulolytic bacterial isolates from Muntjac, Deer and Anoa feces have similar pattern, and was different from the growth pattern of bacterial isolates from bison feces. The optimal growth point of cellulolytic bacterial isolates from the feces of Muntjac, Deer, and Anoa at the 8th hour of incubation with bacterial populations of 1.3 x 109 CFU mL-1, 1.7 x 109 CFU mL-1, and 1.4 x 109 CFU mL-1. The growth pattern and optimal point of cellulolytic bacterial isolates from the feces of Bison at the 12th hour after incubation with bacterial populations of 1,1 x 1010 CFU mL-1. The addition of cellulolytic bacterial isolates did not affect microbial protein synthesis. [ABSTRACT FROM AUTHOR]

This study focuses on the isolation and identification of cellulose-degrading bacteria from the digestive tract of sheep (Ovis aries) and to determine the cellulase capacity of different isolates for ulterior application. The bacterial strains were screened firstly using Congo red, where cellulase activity is indicated by the appearance of a hydrolysis zone on the Carboxymethylcellulose medium (CMC), the clearance zone value ranged between 8 and 15 mm for all isolates and the hydrolytic capacity was between 1.6 to 2.5 mm. The cellulolytic strain isolates were identified using MALDI-TOF Mass Spectrometry and 16S ribosomal RNA gene sequencing. MALDI-TOF MS test indicated that all strains belonged to Bacillaceae family. The strains Isolate2, Isolate3, and Isolate8 were reliable to B. tequilensis species with a score value 2.0. Whereas, the Isolate1, Isolate4, Isolate5, and Isolate6 were reliably identified to the genus level (Score value 1.7–1.99). The molecular identification results revealed that the strains indicate a high sequence similarity with 16S rRNA gene sequences accessible in GenBank database and belong to Priestia megaterium, Lysinibacillus capsici, Bacillus tequilensis, and Bacillus paralicheniformis. The highest Carboxymethylcellulase activity (CMCase) was obtained by B. tequilensis (0.827 ± 0.035 U/ml) at a pH of 7.0 and temperature of 30 °C at 100 g. The carbon source utilized was CMC (1 %), while peptone (1 %) and ammonium sulfate (0.24 %) served as the nitrogen sources. Further research in optimizing and purifying of cellulase, could be useful for the future hydrolyzation of some green biomass for various biotechnological applications such as biofuel production.

Cellulases are enzymes that hydrolyze the ß-1,4-glycosidic bonds of the cellulose polymer into smaller oligosaccharides and glucose. Today, bacterial cellulases are attracting growing interest due to their potential industrial applications in the detergent, textile, pulp and paper, biofuel and compost industries. The aim of the present study was to characterize cellulolytic bacterial strains isolated from the soils of several woodland ecosystems in the Adamaoua region. To this end, twelve (12) soil samples were taken in five (05) departments with forested ecosystems in the Adamaoua region (Vina, Mbéré, Mayo Banyo, Djerem, Faro and Déo). A total of thirty-five (35) strains were obtained from these samples and screened for cellulolytic activity on Carboxymethylcellulose (CMC) agar. After screening, twenty (27) isolates were able to utilize cellulose as the sole source of carbon and energy by revealing Congo Red decolorization halos on CMC medium. The hydrolysis rate of these strains ranged from 1.65 to 6.65. The strains with the best cellulolytic activity were I2, I3, A3, A4 and H2, with halos ranging from 3.42 to 6.65 respectively. These strains were obtained from the following districts: Lycée Classique et Moderne in Ngaoundéré (Vina) and the Djoumbal and Pedeng districts in Bagno, Mayo Banyo department. This work leads to the conclusion that the undergrowth soils of the Adamaoua region are sources of cellulase-producing cellulolytic bacteria, and their valorization deserves to be investigated. [ABSTRACT FROM AUTHOR]

Red swamp crayfish (Procambarus clarkii) like to eat aquatic plants. The intestinal microorganism plays an important role in cellulose degradation and utilization. Isolating bacteria which can degrade cellulose from the intestines of P. clarkii can provide a theoretical basis for the development of probiotics in forage for P. clarkii. Three selective media including carboxymethyl-cellulose, microcrystalline cellulose, and cellobiose were used in plate cultures for 48h and then dyed with Congo red. It was found that 5 strains produced hydrolytic rings on 3 culture media at 48h. Based on the results of 16S rRNA molecular analysis, strains C, E, G, H, and M were identified as Citrobacter sp., Staphylococcus sp., Acinetobacter johnsonii, Shewanella sp., and Aeromonas caviae, respectively. Specifically, Staphylococcus sp. exhibited the strongest capacity for the degradation of cellulose. Shewanella sp. showed the strongest degradation capacity for cellobiose. Acinetobacter johnsonii and Shewanella sp. can degrade cellulose and are expected to be used as probiotic feed for P. clarkii. This study can provide a theoretical basis for the healthy culture of P. clarkii. [ABSTRACT FROM AUTHOR]

The article presents a study which investigated the efficiency of neem leaf extract on the control of wood termite, Coptotermes species, and gut cellulolytic bacteria. Topics discussed include isolation of cellulolytic bacteria from termite gut, identification of cellulolytic bacteria, and preparation of plant bio-pesticide.

The aim of the present study was to assess the effect of replacing the forage portion (alfalfa, corn silage, and barley straw) in the diet of lactating Holstein cows with triticale hay (TH, × Triticosecale L.) on DMI, digestibility, ruminal fermentation variables, estimated microbial-N synthesis (EMNS), and milk production and composition. Eight Holstein cows were used in a replicated Latin square design (two 4 × 4 squares) with four 28-d periods and 4 treatments, including a TH-free diet (control), and diets replacing 33%, 66%, and 100% of the forage portion with TH. Cows were fed ad libitum with 10% carryover during the experimental periods. Intakes and in vivo digestibilities of dry matter, organic matter, crude protein, and ash-free neutral detergent fiber, rumen pH, ammonia-N, total and individual short-chain fatty acids, protozoa, and bacteria populations were evaluated using specific methods. Moreover, in vitro total gas and methane release and in vivo urinary purine derivatives, EMNS, milk production, and composition were measured. The results showed that TH diets lowered DMI, compared with the control. Apparent digestibilities of DM, OM, CP, and NDF increased with dietary TH inclusion. The addition of TH instead of the diet forage portion increased in vivo rumen pH; acetic, propionic, valeric, and isovaleric acids concentrations; cellulolytic bacteria number; and in vitro gas production. In vivo rumen ammonia-N, short-chain fatty acids, butyric acid, in vivo and in vitro total protozoa and Entodiniinae numbers, and in vitro methane production decreased with increasing dietary levels of TH instead of the forage portion. The dietary addition of TH did not affect milk yield, protein, and lactose, but increased fat-corrected milk, milk fat, fat-corrected milk:DMI ratio, and milk yield:DMI ratio. Milk urea N decreased, but urinary purine derivatives excretion and EMNS increased with increasing levels of TH in the diet. For variables with significant changes, except for isovaleric acid, there was a linear response of animals to increasing levels of TH in the diet. Results suggest that TH, which is grown with less water compared with alfalfa, corn forage, and straw, is a potential alternative to those forages by increasing milk production efficiency, milk fat, and decreasing methane emission. [ABSTRACT FROM AUTHOR]

Background and Objectives: Rumen microbiologists are looking for new probiotics to improve the digestibility of livestock diets. This study intended to screen and evaluate the ruminal cellulolytic bacteria (CBs) and their potential application as probiotics. Materials and Methods: Microbial culture and molecular techniques performed to isolate CBs from the rumen of camels, deer and rams. Their antibacterial and antibiogram tests were done using disc diffusion method. Their potential to degrade cellulose, starch, tannin and protein were investigated using clear zone halo, and spectrophotometric techniques. Bilious, saline, and acidic broth media were used to study the resistance of isolates in intestinal conditions. Results: The phylogenetic analysis revealed that the strains belonged to Firmicutes and Proteobacteria phyla, Citrobacter murliniae, Ornithinibacillus bavariensis, C. braakii, and Bacillus subtilis. The highest cellulase (CAS) activity was recorded by C. murliniae Dez wildlife13A (2.98 UmL-1), whereas C. braakii Loot desert 111A (1.14 Uml-1) was produced the lowest enzyme. The isolates were highly resistant to synthetic conditions of intestine (pH 2.5-3.5, bile 0.3-2%), as well as tolerated higher concentrations of NaCl (up to 10%). They effectively inhibited standard pathogen strains, and showed sensitivity to the used antibiotics. Conclusion: This study reports the cellulolytic O. bavariensis Tabbas desert 32A for the first time from the rumen, which will have potential biotechnological applications. [ABSTRACT FROM AUTHOR]

Purpose: Application of cellulolytic bacteria for hydrogen production has dual benefits in the removal of wastes and as a source of energy without prior treatment strategies. The main purpose of the current study to investigate the effect of calcium oxide (CaO) nanoparticles on the dark fermentative generation of hydrogen by a pure cellulolytic bacterial strain using wheat bran as a lignocellulosic feedstock. Method: In the current study, cellulose-decomposing bacteria Rossellomorea marisflavi strain Asu10 was tested for dark fermentative biohydrogen production using wheat bran as a substrate. The impact of calcium chloride (CaCl2) and CaONPs on biohydrogen production was assessed. Results: The results revealed that the optimum conditions for bacterial utilization of wheat bran were at pH 7.0, 20 g/L substrate concentration, and 120 rpm shaking after 48 h. The optimum hydrogen yields obtained were 2.1 and 0.9 mol H2/mole reducing sugars in a wheat bran fermentation media supplemented with 20 µg/mL of CaONPs and CaCl2; respectively. The optimum energy conversion efficiency (50.2%) was detected at the same concentration of CaONPs. However, the optimum wheat bran saccharification yield (112.5%) was determined at 10 µg/mL CaONPs. Conclusion: The current study suggests the application of cellulolytic isolate R. marisflavi strain Asu10 as a promising tool for the renewable production of biohydrogen from agricultural lignocellulosic substrates without the need for pretreatment, the use of CaONPs as a catalyst to increase bio-H2 productivity by strain. [ABSTRACT FROM AUTHOR]

Species belonging to the genus Bacillus produce many advantageous extracellular enzymes that have tremendous applications on a commercial scale for the textile, detergent, feed, food, and beverage industries. This study aimed to isolate potent thermo-tolerant amylolytic and cellulolytic bacterium from the local environment. Using the Box–Behnken design of response surface methodology, we further optimized the amylase and cellulase activity. The isolate was identified by 16S rRNA gene sequencing as Bacillus subtilis QY4. This study utilized potato peel waste (PPW) as the biomaterial, which is excessively being dumped in an open environment. Nutritional status of the dried PPW was determined by proximate analysis. All experimental runs were carried out in 250 mL Erlenmeyer flasks containing acid treated PPW as a substrate by the thermos-tolerant Bacillus subtilis QY4 incubated at 37 °C for 72 h of submerged fermentation. Results revealed that the dilute H2SO4 assisted autoclaved treatment favored more amylase production (0.601 IU/mL/min) compared to the acid treatment whereas high cellulase production (1.269 IU/mL/min) was observed in the dilute acid treatment and was found to be very effective compared to the acid assisted autoclaved treatment. The p-value, F-value, and coefficient of determination proved the significance of the model. These results suggest that PPW could be sustainably used to produce enzymes, which offer tremendous applications in various industrial arrays, particularly in biofuel production. [ABSTRACT FROM AUTHOR]

Biofuels are the cheapest source of energy, and the continuous decline of traditional sources of energy with the increasing population leads to looking for alternatives to reduce the consumption of traditional sources of energy. Bioethanol production from lignocellulosic wastes and cellulosic wastes is not a new approach for fuel production but a cheap and accessible way for the production of fuel. Bacillus is one of the major species that can act as a source of diversified enzymes. In this study, it was emphasized on screening and isolation of a novel, characterization, and best catalytic action on both celluloses and proteins in the presence of different carbon and nitrogen sources. It was observed the effective catalytic breakdown of cellulose with the crude enzyme to glucose allowed fur for fermentation with Saccharomyces, ultimately leading to the generation of alcohol. The study aims to isolate the microbes that can produce cellulases and enzymes and could be used for biodegradation to produce ethanol in the reaction. The maximum enzyme activity was achieved at 3.112 UI with optimized pH and temperature, and the maximum conversion of sugars into alcohol was about 70% in the newspaper, cartons, colored paper, and disposable paper cups. An essential observation was the decolorization of the origami craft paper within 24 hours. The study was involved in enhancing the maximum Enzyme activity of cellulases from different cellulosic raw materials. Hence, it was achieved by JCB strain, optimization of pH, temperature, and acids for the biodegradation. The presence of peaks at 3200 and 2900 was a confirmation of ethanol bonds in the biodegradation reaction mixtures. [ABSTRACT FROM AUTHOR]

Staphylococcus cohnii (Schleifer and Kloos) an opportunistic pathogen for humans, is reported for the first time its presence in grubs of Brahmina coriacea (Hope) (Coleoptera, Scarabaeidae, Melolonthinae). The cellulolytic gut bacteria were isolated from different populations of B. coriacea, collected from different parts of Himachal Pradesh, India. The isolated S. cohnii from the grub population of Shillaroo location recorded maximum cellulolytic index. The isolated bacteria were identified using morphological, biochemical, and 16S rRNA gene sequencing approaches. [ABSTRACT FROM AUTHOR]

Consolidated bioprocessing (CBP) of lignocellulosic biomass holds promise to realize economic production of second-generation biofuels/chemicals, and Clostridium thermocellum is a leading candidate for CBP due to it being one of the fastest degraders of crystalline cellulose and lignocellulosic biomass. However, CBP by C. thermocellum is approached with co-cultures, because C. thermocellum does not utilize hemicellulose. When compared with a single-species fermentation, the co-culture system introduces unnecessary process complexity that may compromise process robustness. In this study, we engineered C. thermocellum to co-utilize hemicellulose without the need for co-culture. By evolving our previously engineered xylose-utilizing strain in xylose, an evolved clonal isolate (KJC19-9) was obtained and showed improved specific growth rate on xylose by ∼3-fold and displayed comparable growth to a minimally engineered strain grown on the bacteria's naturally preferred substrate, cellobiose. To enable full xylan deconstruction to xylose, we recombinantly expressed three different β-xylosidase enzymes originating from Thermoanaerobacterium saccharolyticum into KJC19-9 and demonstrated growth on xylan with one of the enzymes. This recombinant strain was capable of co-utilizing cellulose and xylan simultaneously, and we integrated the β-xylosidase gene into the KJC19-9 genome, creating the KJCBXint strain. The strain, KJC19-9, consumed monomeric xylose but accumulated xylobiose when grown on pretreated corn stover, whereas the final KJCBXint strain showed significantly greater deconstruction of xylan and xylobiose. This is the first reported C. thermocellum strain capable of degrading and assimilating hemicellulose polysaccharide while retaining its cellulolytic capabilities, unlocking significant potential for CBP in advancing the bioeconomy. [Display omitted] • Second generation biofuel (biohydrogen) from consolidated bioprocessing of biomass. • Clostridium thermocellum is engineered to co-utilize cellulose and hemicellulose. • Growth on xylan by C. thermocellum is achieved by expression of β-xylosidase. • β-xylosidase reduces xylan degradation intermediates, xylo-oligomers and xylobiose. • Hemicellulose utilization increases hydrogen yield by 20%. [ABSTRACT FROM AUTHOR]

Copyright of Ecosistemas y Recursos Agropecuarios is the property of Universidad Juarez Autonoma de Tabasco and its content may not be copied or emailed to multiple sites or posted to a listserv without the copyright holder's express written permission. However, users may print, download, or email articles for individual use. This abstract may be abridged. No warranty is given about the accuracy of the copy. Users should refer to the original published version of the material for the full abstract. (Copyright applies to all Abstracts.)

Copyright of Ecosistemas y Recursos Agropecuarios is the property of Universidad Juarez Autonoma de Tabasco and its content may not be copied or emailed to multiple sites or posted to a listserv without the copyright holder's express written permission. However, users may print, download, or email articles for individual use. This abstract may be abridged. No warranty is given about the accuracy of the copy. Users should refer to the original published version of the material for the full abstract. (Copyright applies to all Abstracts.)

Enzyme-production microorganisms typically occupy a dominant position in composting, where cellulolytic microorganisms actively engage in the breakdown of lignocellulose. Exploring strains with high yields of cellulose-degrading enzymes holds substantial significance for the industrial production of related enzymes and the advancement of clean bioenergy. This study was inclined to screen cellulolytic bacteria, conduct genome analysis, mine cellulase-related genes, and optimize cellulase production. The potential carboxymethylcellulose-hydrolyzing bacterial strain Z2.6 was isolated from the maturation phase of pig manure-based compost with algae residuals as the feedstock and identified as Bacillus velezensis. In the draft genome of strain Z2.6, 31 related cellulolytic genes were annotated by the CAZy database, and further validation by cloning documented the existence of an endo-1,4-β-D-glucanase (EC 3.2.1.4) belonging to the GH5 family and a β-glucosidase (EC 3.2.1.21) belonging to the GH1 family, which are predominant types of cellulases. Through the exploration of ten factors in fermentation medium with Plackett–Burman and Box–Behnken design methodologies, maximum cellulase activity was predicted to reach 2.98 U/mL theoretically. The optimal conditions achieving this response were determined as 1.09% CMC-Na, 2.30% salinity, and 1.23% tryptone. Validation under these specified conditions yielded a cellulose activity of 3.02 U/mL, demonstrating a 3.43-fold degree of optimization. In conclusion, this comprehensive study underscored the significant capabilities of strain Z2.6 in lignocellulolytic saccharification and its potentialities for future in-depth exploration in biomass conversion. [ABSTRACT FROM AUTHOR]

The municipal landfills contain substantial amounts of lignocellulosic waste that have not been adequately utilized. This waste can be processed using cellulolytic bacteria. Cellulolytic bacteria play an important role in the degradation of cellulose-based materials. This study aimed to isolate and identify cellulolytic bacteria based on 16S rDNA sequence obtained from the Supit Urang municipal landfill, Malang City. Bacteria were isolated from soil by cultivating on 1% carboxyl methyl cellulose (CMC) agar media. The cellulolytic activity was analyzed semi-quantitatively with flooded 1% Congo red and then washed with 1 M NaCl three times. Cellulase activity assay was measured using the 3.5-Dinitrosalicylic Acid (DNS) method. The most potential isolate in cellulose decomposition was identified. The most potential isolate in cellulose decomposition was identified. Twenty isolates of cellulolytic bacteria were obtained from the sample and sixteen isolates formed the clear zone. The cellulolytic index ranged between 0.26 and 1.52. Five isolates, SL1, SL2, SL10, SL16, and SL19 had the highest cellulolytic index. Isolate SL2 had the highest cellulase activity at 0.071 U/mL. Based on the 16S rDNA sequence, SL2 was identified as Bacillus amyloliquefaciens F98 with a similarity of 99.02%. This potential isolate has prospects for the biodegradation process from agricultural waste, which can be processed into valuable products.

ARTICLE HIGLIGHTS - Fermetodege as a source of cellulolytic bacteria that degrade cellulosic materials. - Enhances ruminant feed by improving palatability and digestibility. - Utilizes water hyacinth, reducing invasive plant spread and supporting ecosystems. - Bioprospecting reveals new bacteria for effective fermentation starter development. ABSTRACT Fermetodege is a name of fermented ruminant feed produced from free heavy metals water hyacinth, rice bran, and corn cobs. Its quality, as well as the fermentation process, are affected by numerous factors, such as the diversity, evenness, and dominance of indigenous cellulolytic bacterial species. A proper understanding of these influential factors is needed to improve the quality of the fermented feed. Therefore, this study aims to evaluate the diversity, evenness, and dominance of cellulolytic bacteria isolated from fermetodege. The cellulolytic activity of the isolates was tested by observing their growth on the carboxymethylcellulose (CMC) media. Isolates with cellulolytic activity formed a clear zone after the colonies were soaked with 0.1% Congo red and rinsed with 1 M NaCl. The Shannon-Weiner's diversity and evenness indexes, as well as Simpson's species dominance, were then calculated. The result showed that the Shannon-Weiner’s diversity index ranged from 0.6849 to 1.8173, and it was categorized as medium. The evenness index was between 0.7778 and 0.9983, which indicates a stable distribution of species. Meanwhile, the Simpson’s species dominance ranged from 0.1835 to 0.5082, which implies that none of the species was dominant. These results show that fermetodege is potentially a source of bacterial isolates and can be used as a fermentation consortium starter.

Lignocellulose is a core component of plant biomass and the most abundant carbohydrate polymer in nature. It is cheap and renewable and has several potential applications; however, it remains underutilized because of its recalcitrance to degradation. Cellulolytic microbes have been found in the gut of herbivorous insects, such as grasshoppers. This study aimed to isolate lignocellulolytic bacteria from the gut of grasshoppers (Oxya chinensis) and determine their diversity and potential biomass-degrading activity. A total of 27 culturable isolates were obtained from the grasshopper foregut, midgut, and hindgut. The bacteria hydrolyzed cellulose and lignin, as indicated by a cellulolytic index of 0.12–1.23 and ligninolytic index of 0.1–1.47. Five potential cellulolytic bacterial isolates were selected. Based on 16S rRNA sequencing, the isolates were identified as Bacillus wiedmannii (foregut), Bacillus marcorestinctum, Bacillus halotolerans (midgut), Paenibacillus zanthoxyli, and Bacillus hominis (hindgut). The highest specific cellulolytic activity (0.0068 U/mg) was detected in B. wiedmannii (OCF2), which could be exploited as a potential source of cellulases.

In the present study, biological indicators were used to assess the impact of applying spent mushroom substrate and manure on the soil environment. The use of spent mushroom substrate had a varied effect on the microorganisms. Stimulation was recorded in the abundance of copiotrophic bacteria and fungi, but only in the first year of the study. In the case of cellulolytic bacteria, this effect was visible only in single plots. Similar observations were also noted regarding the relative DNA content (in relation to the control), which increased for both bacteria and fungi after applying spent mushroom substrate. In the soil fertilized with spent mushroom substrate, a decrease in DNA concentration was observed, but only in the first and second year. For enzymatic activity, the use of spent mushroom substrate alone proved to be more favorable, but this effect was again observed only in the first year of the study. The application of manure caused similar changes as observed with the use of spent mushroom substrate. These observations indicate a similar impact of spent mushroom substrate and manure on the parameters tested. The research presented suggests the use of both classical methods and methods based on the analysis of DNA extracted from soil to study the impact of spent mushroom substrate on the activity of soil microbial populations. [ABSTRACT FROM AUTHOR]

Agricultural by-products are frequently used to feed livestock, but they often have low nutritional value. This study was conducted to improve nutritional value of wheat straw using cellulolytic bacteria isolated from the foregut of dromedary camel. Rumen fluid was collected from four fistulated camels. The cellulose-hydrolytic bacteria were isolated by using medium amended with carboxymethyl cellulose (CMC). The activity of carboxymethyl cellulase (CMCase) was determined by measuring the release of reducing sugars. The optimum pH and temperature for growth and CMCase activity of the isolates were determined. Three isolates (SH13, SH2, and SH22) showed maximum hydrolysis capacity and were selected for further investigation. The analysis of 16S rRNA gene sequences of these isolates showed that the isolates possessed 99, 94 and 98% similarity with Escherichia coli, and Enterobacteriaceae, respectively. Wheat straw was incubated with the isolated bacteria in liquid medium for 6 weeks. The results showed inoculation with SH22 isolates resulted in the highest disappearance of dry matter and crude protein content, and the lowest amount of neutral detergent fibre (NDF), iNDF and acid detergent fibre (ADF). Treatment with SH13 isolate had the highest digestibility of NDF and ADF, and treatment with SH2 had the highest truly degraded organic matter (TDOM) and partitioning factor (PF). Our data suggest that maybe bacteria isolated from camel foregut can increase digestibility and enhancing nutrition value of wheat straw. [ABSTRACT FROM AUTHOR]

Plant biomass has cellulose as major component of plant cell walls in lignocellulosic form. For carbon cycle, the degradation and cellulosic biomass utilization is necessary. There are many cellulolytic strains including aerobic, anaerobic, mesophilic, thermophilic and alkaliphilic bacteria which can utilize the cellulose as carbon source. In present study a bacterial culture was isolated from rhizosphere soil. On primary screening by Carboxy methyl cellulose agar plate method, five bacterial isolate (M2, M4, M5, M+V1, M+V2) showed positive results. Morphological, biochemical and molecular characterization was used for identification of isolates. Shake flask fermentation was employed to produce cellulase enzyme and crude enzyme was extracted. The cellulase activity of five different isolates M2, M4, M5, M+V1, M+V2 noticed was 99.71, 32.29, 120.16, 41.6 and 96.499 μmol/ml minute, respectively. M5 isolate has shown maximum cellulase activity at pH 7.0 after 24 hours. M5 isolate was identified as Bacillus cereus by 16SrRNA sequencing. [ABSTRACT FROM AUTHOR]

Introduction: Saccharomyces cerevisiae is one of the most common probiotics used in ruminant nutrition. Saccharomyces cerevisiae increase gas production through specific biochemical mechanisms. Some of these mechanisms, based on the yeast's ability to excrete excess oxygen from the rumen, create a better space for ruminal anaerobic bacteria. The yeast Saccharomyces cerevisiae can provide a place for metabolic exchange and a suitable environment for the growth and activity of beneficial microorganisms around the substrates. On the other hand, increased gas production by adding yeast may be due to increased propionate fatty acid production due to improved ruminal fermentation. Because carbon dioxide is produced by some rumen bacteria through the succinatepropionate pathway when propionate is produced. Because the fermentation of dietary carbohydrates into volatile fatty acids produces gases in the rumen that are mainly hydrogen, carbon dioxide, and methane, the addition of yeast not only has the potential to improve gas production, but can cause qualitative changes in the gases produced and reduce the negative impact on the environment. The addition of yeast in concentrated diets increased the population of fiber decomposing microorganisms compared to the control group without adding yeast (Callaway& Martin 1997; Dehghan-Banadaky et al. 2012). Yeast also directly stimulates ruminal fungi, which may improve fiber digestion. Gas production forms the basis of any substrate, mainly dependent on the availability of nutrients for ruminal microorganisms it is quite clear that the increase in gas production was due to the increase in crude protein content. It is well known that Saccharomyces cerevisiae can reduce the production of ammonia in the rumen. Ammonia emissions from cattle manure reduces by reducing protein degradation and overall nitrogen excretion by the animal. The direct result of this action is an increase in protein bypass in the rumen, which is absorbed and metabolized as a real protein in the gastrointestinal tract and small intestine. Reducing the latency phase by increasing the protein content (for example, a diet with higher crude protein) indicates the rapid activity of Saccharomyces cerevisiae on the fermentation process. In addition, Saccharomyces cerevisiae contains small peptides and other nutrients that are needed by the dominant ruminal cellulite bacteria to initiate growth. The activity of Saccharomyces cerevisiae depends on many factors, including the availability of nutrients to rumen microorganisms, which stimulates the fermentation process (Newbold et al. 1995). This study aimed to investigate the effects of yeast supplementation on fermentation parameters in total mixed rations in vitro. Materials and methods: Accordingly, the effect of 4 levels of yeast supplementation involved, zero, 4, 8, and 12 mg/g of yeast in two TMR diets containing 60 and 70% of concentrates, on the kinetics and parameters of gas production, rumen fermentation parameters including pH, ammonia nitrogen, concentration and profiles of volatile fatty acids, and true digestibility of dry matter and neutral detergent fibers were evaluated. In addition, the effect of yeast supplementation on the population of protozoa, anaerobic fungi, and cellulolytic microorganisms were evaluated using molecular techniques. In this experiment, three adult Holstein steers equipped with ruminal fistulas were used to prepare ruminal fluid. For the polymerase chain reaction, after sequencing of the primers, the extracted DNA was amplified using PCR to check primer specificity. DNA amplification was examined by the system (R-T PCR) with three replications for each pair of primers. Results and discussion: The addition of different levels of Saccharomyces cerevisiae supplementation caused a significant increase (P<0.05) in the amount of gas produced by increasing the incubation time of experimental diets. The results show that there is a statistically significant difference (P<0.05) between different levels of supplementation; so that from 24 hours after incubation onwards, the highest amount of gas produced in the experimental diets was at the level of 12 mg/g supplement was observed. The addition of different levels of Saccharomyces cerevisiae supplementation caused a significant increase (P<0.05) in the total amount of VFA produced in the rumen with increasing levels of supplementation in experimental diets. The results show that there is a statistically significant difference (P<0.05) between different levels of supplementation so that the highest amount of total VFA produced in both diets was observed at the level of 12 mg/g supplement. The effect of adding different levels of Saccharomyces cerevisiae supplementation on ruminal parameters caused a significant increase (P<0.05) in ruminal pH and a decrease in ruminal ammonia production by increasing the level of supplementation in experimental diets. The results show that there is a statistically significant difference between different levels of supplementation so that the greatest increase in ruminal pH and decrease in ammonia production in experimental diets at the level of 12 mg/g. The effect of diet type was also significantly different (P<0.05). The highest increase in ruminal pH and decrease in ammonia production was observed in diets containing 60% concentrate. The results of this study showed that the yeast supplementation in high fermentative TMR diets increased (P<0.05) the rumen environmental stability, increased (P<0.05) the fermentability of dietary insoluble fraction, reduced (P<0.05) the gas production rate and reduced (P<0.05) the lag phase. addition of Saccharomyces cerevisiae in higher crude protein diets, improved of the dry matter digestibility. Nutrient analysis without affecting the digestibility of insoluble fibers in neutral detergent and the digestibility of soluble fibers in acidic detergent with diets containing higher crude vitamin, even with the addition of Saccharomyces cervicia, improved dry matter digestibility and organic matter digestibility. However, Saccharomyces cerevisiae only affects the edibility of the desiccant. Both diets had different crude production. Therefore, improving the treatability of dry matter and the edibility of organic matter was the result of increasing the raw material, which improved micro activities in the rumen. Conclusions: Yeast supplementation improved fiber digestibility and reduced lactate accumulation and LPS concentration by stabilizing the anaerobic environment in the rumen and stimulating the growth and activity of fiber-degrading microorganisms. [ABSTRACT FROM AUTHOR]

Lignocellulose is a core component of plant biomass and the most abundant carbohydrate polymer in nature. It is cheap and renewable and has several potential applications; however, it remains underutilized because of its recalcitrance to degradation. Cellulolytic microbes have been found in the gut of herbivorous insects, such as grasshoppers. This study aimed to isolate lignocellulolytic bacteria from the gut of grasshoppers (Oxya chinensis) and determine their diversity and potential biomass-degrading activity. A total of 27 culturable isolates were obtained from the grasshopper foregut, midgut, and hindgut. The bacteria hydrolyzed cellulose and lignin, as indicated by a cellulolytic index of 0.12-1.23 and ligninolytic index of 0.1-1.47. Five potential cellulolytic bacterial isolates were selected. Based on 16S rRNA sequencing, the isolates were identified as Bacillus wiedmannii (foregut), Bacillus marcorestinctum, Bacillus halotolerans (midgut), Paenibacillus zanthoxyli, and Bacillus hominis (hindgut). The highest specific cellulolytic activity (0.0068 U/mg) was detected in B. wiedmannii (OCF2), which could be exploited as a potential source of cellulases. [ABSTRACT FROM AUTHOR]

Introduction: Every year, a significant amount of saffron petals remains as a by-product after harvesting and separating the thread-like parts of the flower (stigmas). The saffron stigma constitutes only 7.4% of the flower's weight and the remaining 92.6% is unused. This plant residue (petals) is a valuable source of plant bioactive compounds (phytobiotics), which based on previous studies, has useful effects on rumen fermentation, digestion and diet efficiency. However, there is no specific information about the effect of this by-product on ruminal microbial populations, enzymatic activity, antioxidant health, as well as the mechanism of effectiveness. In the present study, it was hypothesized that the use of low levels of saffron petals in the diet (as a natural additive) could improve microorganism populations, hydrolytic enzymes and antioxidant health of the rumen. Therefore, this research was carried out to investigate the mechanism of the positive effects of saffron petals on the energy and nitrogen metabolism and antioxidant health of the sheep rumen using the in vitro method. Materials and Methods: Experimental treatments included a diet without saffron petals (control) and diets containing 1, 2, and 3% of saffron petals (based on dry matter). The 24 and 72-h gas production tests were performed in 2 series (runs; in different weeks) and 3 replicates in each run (i.e., 6 observations per treatment at each incubation time). The gas production from the samples incubated in the 100-mL glass syringes was recorded. Then, the protozoa (using a hemocytometer and light microscope), cellulolytic and proteolytic bacteria (using liquid medium and Hungate tubes), hydrolytic enzymes (via chemical methods and photometry), methane (by injecting NaOH solution to absorb CO2) and antioxidant capacity (via ferric reducing antioxidant power assay) were measured. Truly degraded substrate was determined by boiling fermentation residues in the neutral detergent solution and weighing, ammonia-N by phenol-hypochlorite method, and the volatile fatty acids (VFA) using gas chromatography. Microbial biomass production, digestibility, metabolizable energy and partitioning factor were estimated using the equations. Data were analyzed using the Proc GLM of SAS 9.1 in a completely randomized design (6 observations per treatment). Results and Discussion: The inclusion of different levels of saffron petals in the diet decreased the in vitro ruminal protozoa population (P<0.05), due to its bioactive components, which damage the structure and function of the protozoa membrane, deactivate protozoa enzymes or deprive protozoa of the substrate and metal ions needed for their metabolism. Moreover, saffron petals increased the cellulolytic bacteria numbers and microbial biomass production (P<0.05). This was due to the reduction of protozoa, which leads to the reduction of the bacteria predation and thus improves the growth and population of the cellulolytics. The ruminal fibrolytic enzymes and amylase activity decreased with the use of saffron petals in the diet (P<0.05), because of the higher cellulolytic bacteria and microbial biomass, i.e., higher bacteria activity. These improvements resulted in more (P<0.05) diet digestibility, metabolizable energy, total VFA and truly degraded substrate in the saffron petals-containing groups. The inclusion of saffron petals in the diet resulted in decreasing in vitro ruminal methane release, ammonia-N production and acetate-to-propionate ratio (P<0.05). These changes were due to the decreased protozoa numbers leading to less hydrogen supply for methanogens and higher hydrogen shift toward propionate, as well as less deamination process and ruminal nitrogen recycling. Another reason was the increase of cellulolytic bacteria that consume ammonia as their main nitrogen source. Antioxidant capacity increased with the use of saffron petals in the diet (P<0.05), due to the bioactive compounds and antioxidants (such as flavonoids) present in this plant residue. The maximum truly degraded substrate was observed in the diet containing 3% of saffron petals. The lowest methane, protozoa and ammonia were in diets containing 2 and 3% of saffron petals. Moreover, adding 2 and 3% of saffron petals caused the highest antioxidant power. Conclusion: The results showed that the positive effect of saffron petals on the ruminal metabolism and antioxidative health of sheep, in vitro, was due to the beneficial changes that occurred in microbial populations (increase of cellulolytic bacteria and decrease of protozoa), hydrolytic enzymes (fibrolytic enzymes and amylase) and its antioxidants. Therefore, low levels (up to 3% of diet) of saffron petals can be used as a natural phytobiotic additive to improve rumen fermentation and reduce loss of energy and nitrogen resources, although it is better to confirm the results in vivo. Conflict of Interest: The authors declare no potential conflict of interest related to the work. [ABSTRACT FROM AUTHOR]

Objective: To isolate and characterize cellulolytic rumen bacteria from the rumen of Sahiwal cattle using rumen bacterial inoculum to increase the nutritional value of rice bran used as broiler feed. Materials and Methods: The ruminal liquid was kept at an optimal pH of 6.9 and a redox potential of less than -300 mV while being incubated anaerobically at 39°C in a medium containing rumen fluid glucose cellobiose agar. By using the Hungate technique, the organisms were detected based on their morphological, physiological, biochemical, and molecular testing. Results: The findings revealed that the isolated Ruminococcus albus, and Ruminococcus flavifaciens were obligate anaerobic, generally Gram-positive, nonmotile cocci or rod, single or pair, occasionally short chain, producing yellow pigment when grown on cellulose, and having a clear zone around the colonies. Both isolate fermented sugars such as cellobiose, glucose, and lactose, as well as decomposed xylan. The results also showed that the isolates recognized as Ruminococcus spp., a cellulolytic rumen bacterium, were catalase-negative, indole-negative, and gelatin liquefaction-positive. Conclusion: Isolation and characterization of Ruminococcus spp. may be helpful for Bangladesh in reducing the cost of producing poultry feed and circumventing restrictions on rice bran use. We can also develop more efficient and long-lasting plans to enhance poultry performance and feed efficiency, as well as increase the nutritional value of rice bran used as broiler feed, by understanding how various Ruminococcus spp. function in this process. [ABSTRACT FROM AUTHOR]

Copyright of Xinjiang Agricultural Sciences is the property of Xinjiang Agricultural Sciences Editorial Department and its content may not be copied or emailed to multiple sites or posted to a listserv without the copyright holder's express written permission. However, users may print, download, or email articles for individual use. This abstract may be abridged. No warranty is given about the accuracy of the copy. Users should refer to the original published version of the material for the full abstract. (Copyright applies to all Abstracts.)

Simple Summary: Lignocellulose, consisting of cellulose, hemicellulose, and lignin, constitutes 60% of Earth's biomass and plays a critical role in the carbon cycle. Abundantly found in plant leaves and stems, cellulose undergoes biodegradation predominantly by cellulolytic microorganisms that produce cellulases. This process is particularly vital for the breakdown of crystalline cellulose in plant cell walls. The effective degradation of cellulose in natural environments hinges on the accurate identification of truly cellulolytic bacteria. This review compiles and analyzes data from the past 11 years on such bacteria, derived from forest and agricultural soils, and offers insights into the functions of cellulolytic bacteria and their cellulase enzymes. This review provides insights into cellulolytic bacteria present in global forest and agricultural soils over a period of 11 years. It delves into the study of soil-dwelling cellulolytic bacteria and the enzymes they produce, cellulases, which are crucial in both soil formation and the carbon cycle. Forests and agricultural activities are significant contributors to the production of lignocellulosic biomass. Forest ecosystems, which are key carbon sinks, contain 20–30% cellulose in their leaf litter. Concurrently, the agricultural sector generates approximately 998 million tons of lignocellulosic waste annually. Predominant genera include Bacillus, Pseudomonas, Stenotrophomonas, and Streptomyces in forests and Bacillus, Streptomyces, Pseudomonas, and Arthrobacter in agricultural soils. Selection of cellulolytic bacteria is based on their hydrolysis ability, using artificial cellulose media and dyes like Congo red or iodine for detection. Some studies also measure cellulolytic activity in vitro. Notably, bacterial cellulose hydrolysis capability may not align with their cellulolytic enzyme production. Enzymes such as GH1, GH3, GH5, GH6, GH8, GH9, GH10, GH12, GH26, GH44, GH45, GH48, GH51, GH74, GH124, and GH148 are crucial, particularly GH48 for crystalline cellulose degradation. Conversely, bacteria with GH5 and GH9 often fail to degrade crystalline cellulose. Accurate identification of cellulolytic bacteria necessitates comprehensive genomic analysis, supplemented by additional proteomic and transcriptomic techniques. Cellulases, known for degrading cellulose, are also significant in healthcare, food, textiles, bio-washing, bleaching, paper production, ink removal, and biotechnology, emphasizing the importance of discovering novel cellulolytic strains in soil. [ABSTRACT FROM AUTHOR]

Cellulolytic microorganisms play a crucial role in agricultural waste disposal. Strain QXD-8T was isolated from soil in northern China. Similarity analyses of the 16S rRNA gene, as well as the 120 conserved genes in the whole-genome sequence, indicate that it represents a novel species within the genus Microbacterium. The Microbacterium sp. QXD-8T was able to grow on the CAM plate with sodium carboxymethyl cellulose as a carbon source at 15 °C, forming a transparent hydrolysis circle after Congo red staining, even though the optimal temperature for the growth and cellulose degradation of strain QXD-8T was 28 °C. In the liquid medium, it effectively degraded cellulose and produced reducing sugars. Functional annotation revealed the presence of encoding genes for the GH5, GH6, and GH10 enzyme families with endoglucanase activity, as well as the GH1, GH3, GH39, and GH116 enzyme families with β-glucosidase activity. Additionally, two proteins in the GH6 family, one in the GH10, and two of nine proteins in the GH3 were predicted to contain a signal peptide and transmembrane region, suggesting their potential for extracellularly degrade cellulose. Based on the physiological features of the type strain QXD-8T, we propose the name Microbacterium psychrotolerans for this novel species. This study expands the diversity of psychrotolerant cellulolytic bacteria and provides a potential microbial resource for straw returning in high-latitude areas at low temperatures. [ABSTRACT FROM AUTHOR]

ABSTRACT Locusta migratoria is an important phytophagous pest, and its gut microbial communities play an important role in cellulose degradation. In this study, the gut microbial and cellulose digestibility dynamics of Locusta migratoria were jointly analyzed using high-throughput sequencing and anthrone colorimetry. The results showed that the gut microbial diversity and cellulose digestibility across life stages were dynamically changing. The species richness of gut bacteria was significantly higher in eggs than in larvae and imago, the species richness and cellulose digestibility of gut bacteria were significantly higher in early larvae (first and second instars) than in late larvae (third to fifth instars), and the diversity of gut bacteria and cellulose digestibility were significantly higher in imago than in late larvae. There is a correlation between the dynamics of gut bacterial communities and cellulose digestibility. Enterobacter, Lactococcus, and Pseudomonas are the most abundant genera throughout all life stages. Six strains of highly efficient cellulolytic bacteria were screened, which were dominant gut bacteria. Carboxymethyl cellulase activity (CMCA) and filter paper activity (FPA) experiments revealed that Pseudomonas had the highest cellulase enzyme activity. This study provides a new way for the screening of cellulolytic bacteria and lays the foundation for developing insects with significant biomass into cellulose-degrading bioreactors.IMPORTANCECellulose is the most abundant and cheapest renewable resource in nature, but its degradation is difficult, so finding efficient cellulose degradation methods is an urgent challenge. Locusta migratoria is a large group of agricultural pests, and the large number of microorganisms that inhabit their intestinal tracts play an important role in cellulose degradation. We analyzed the dynamics of Locusta migratoria gut microbial communities and cellulose digestibility using a combination of high-throughput sequencing technology and anthrone colorimetry. The results revealed that the gut microbial diversity and cellulose digestibility were dynamically changed at different life stages. In addition, we explored the intestinal bacterial community of Locusta migratoria across life stages and its correlation with cellulose digestibility. The dominant bacterial genera at different life stages of Locusta migratoria were uncovered and their carboxymethyl cellulase activity (CMCA) and filter paper activity (FPA) were determined. This study provides a new avenue for screening cellulolytic bacteria and lays the foundation for developing insects with significant biomass into cellulose-degrading bioreactors.

ABSTRACT: To maintain membrane homeostasis, ruminal bacteria synthesize branched-chain fatty acids (BCFA) or their derivatives (vinyl ethers) that are recovered during methylation procedures as branched-chain aldehydes (BCALD). Many strains of cellulolytic bacteria require 1 or more branched-chain volatile fatty acid (BCVFA). Therefore, the objective of this study was to investigate BCVFA incorporation into bacterial lipids under different dietary conditions. The study was an incomplete block design with 8 continuous culture fermenters used in 4 periods with treatments (n = 4) arranged as a 2 × 2 × 2 factorial. The factors were high (HF) or low forage (LF, 67 or 33% forage, 33:67 alfalfa:orchardgrass), without or with supplemental corn oil (CO; 3% dry matter, 1.5% linoleic fatty acid), and without or with 2.15 mmol/d (5 mg/d 13C each of isovalerate, isobutyrate, and 2-methylbutyrate). After methylation of bacterial pellets collected from each fermenter's effluent, fatty acids and fatty aldehydes were separated before analysis by gas chromatography and isotope ratio mass spectrometry. Supplementation of BCVFA did not influence biohydrogenation extent. Label was only recovered in branched-chain lipids. Lower forage inclusion decreased BCFA in bacterial fatty acid profile from 9.45% with HF to 7.06% with LF and decreased BCALD in bacterial aldehyde profile from 55.4% with HF to 51.4% with LF. Supplemental CO tended to decrease iso even-chain BCFA and decreased iso even-chain BCALD in their bacterial lipid profiles. The main 18:1 isomer was cis-9 18:1, which increased (P < 0.01) by 25% from CO (data not shown). Dose recovery in bacterial lipids was 43.3% lower with LF than HF. Supplemental CO decreased recovery in the HF diet but increased recovery with LF (diet × CO interaction). Recovery from anteiso odd-chain BCFA and BCALD was the greatest; therefore, 2-methylbutyrate was the BCVFA primer most used for branched-chain lipid synthesis. Recovery in iso odd-chain fatty acids (isovalerate as primer) was greater than label recovery in iso even-chain fatty acids (isobutyrate as primer). Fatty aldehydes were less than 6% of total bacterial lipids, but 26.0% of 13C recovered in lipids were recovered in BCALD because greater than 50% of aldehydes were branched-chain. Because BCFA and BCALD are important in the function and growth of bacteria, especially cellulolytics, BCVFA supplementation can support the rumen microbial consortium, increasing fiber degradation and efficiency of microbial protein synthesis.

ABSTRACTCellulolytic bacteria ferment dietary fiber into short-chain fatty acids, which play an important role in improving fiber utilization and maintaining intestinal health. Safe and effective cellulolytic bacteria are highly promising probiotic candidates. In this study, we isolated three strains of Bacillus cereus, which exhibited cellulolytic properties, from Kele pig feces. To assess the genetic basis of cellulose degradation by the isolates, whole-genome sequencing was used to detect functional genes associated with cellulose metabolism. Subsequently, we identified that the B. cereus CL2 strain was safe in mice by monitoring body weight changes, performing histopathologic evaluations, and determining routine blood indices. We next evaluated the biological characteristics of the CL2 strain in terms of its growth, tolerance, and antibiotic susceptibility, with a focus on its ability to produce short-chain fatty acids. Finally, the intestinal flora structure of the experimental animals was analyzed to assess the intestinal environment compatibility of the CL2 strain. In this study, we isolated a cellulolytic B. cereus CL2, which has multiple cellulolytic functional genes and favorable biological characteristics, from the feces of Kele pigs. Moreover, CL2 could produce a variety of short-chain fatty acids and does not significantly affect the diversity of the intestinal flora. In summary, the cellulolytic bacterium B. cereus CL2 is a promising strain for use as a commercial probiotic or in feed supplement.IMPORTANCEShort-chain fatty acids are crucial constituents of the intestinal tract, playing an important and beneficial role in preserving the functional integrity of the intestinal barrier and modulating both immune responses and the structure of the intestinal flora. In the intestine, short-chain fatty acids are mainly produced by bacterial fermentation of cellulose. Therefore, we believe that safe and efficient cellulolytic bacteria have the potential to be novel probiotics. In this study, we systematically evaluated the safety and biological characteristics of the cellulolytic bacterium B. cereus CL2 and provide evidence for its use as a probiotic.

Objective: Mitragyna speciosa Korth is traditionally used in Thailand. They have a high level of antioxidant capacities and bioactive compounds, the potential to modulate rumen fermentation and decrease methane production. The aim of the study was to investigate the different levels of microencapsulated-Mitragyna leaves extracts (MMLE) supplementation on nutrient degradability, rumen ecology, microbial dynamics, and methane production in an in vitro study. Methods: A completely randomized design was used to assign the experimental treatments, MMLE was supplemented at 0%, 4%, 6%, and 8% of the total dry matter (DM) substrate. Results: The addition of MMLE significantly increased in vitro dry matter degradability both at 12, 24, and 48 h, while ammonia-nitrogen (NH3-N) concentration was improved with MMLE supplementation. The MMLE had the greatest propionate and total volatile fatty acid production when added with 6% of total DM substrate, while decreased the methane production (12, 24, and 48 h). Furthermore, the microbial population of cellulolytic bacteria and Butyrivibrio fibrisolvens were increased, whilst Methanobacteriales was decreased with MMLE feeding. Conclusion: The results indicated that MMLE could be a potential alternative plant-based bioactive compound supplement to be used as ruminant feed additives. [ABSTRACT FROM AUTHOR]

The present study is concerned with the screening the cellulase-producing bacteria from termite gut, assessed potential cellulase-producing bacteria and partial characterization (optimum parameters) of cellulase from isolated bacteria. The result showed that 15 out of 48 isolated strains was positive for degrading the carboxy methyl cellulose (CMC) in agar by congo-red method. After screening by DNS assay, three selected bacteria exhibited high cellulase activity that were identified as Citrobacter amalonaticus CM 1-3, Bacillus cereus CM 5-1 and Streptococcus salivarius CE 5-1 using 16S rRNA sequence analysis. All bacterial strains utilized CMC and showed the highest cellulase activity. Cellulase characterization of C. amalonaticus CM 1-3 and S. salivarius CE 5-1 was revealed optimum activity at 35°C, pH 7.0 and for 48 h. Bacillus cereus CM 5-1 represented its potential use in industrial processes due to thermostable cellulase production. The crude cellulase of this strain was purified by (NH4 )2 SO4 precipitation with 1.58 purification fold and 74.38% overall recovery. The optimal temperature and pH for cellulase activity of B. cereus CM 5-1 were at 40°C and pH 7.0. Thus, this study provided additional information about the diversity and partial characteristic cellulase of cellulolytic bacteria from termite gut for future industrial applications. [ABSTRACT FROM AUTHOR]