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BACKGROUND AND OBJECTIVES: Soil is an essential abiotic component serving as a habitat for numerous organisms, including cellulolytic bacteria commonly found in mangrove ecosystems. This bacteria could produce active enzymes needed to improve environmental quality by accelerating the organic matter decomposition. The unique mangrove environment may contain new types of cellulolytic bacteria with new characteristics. Despite several mangrove areas being explored as sources of cellulolytic bacteria, there is currently unexplored data on its diversity in Aceh Province, Indonesia. Accordingly, it is necessary to analyze the molecular biological approach, namely the 16 svedberg ribosomal ribonucleic acid gene, to identify the diversity of cellulolytic bacteria and analyze the phylogenetic relationships between them. METHODS: Bacteria isolates were collected from mangrove soil at six research locations with three replications. A purposive sampling method was applied to determine the research location. Isolates from soil samples were streaked and purified in carboxymethyl cellulose as selective media for cellulolytic bacteria. Molecular identification adopted 16 svedberg ribosomal ribonucleic acid gene sequencing, and the sequencing data were matched with GenBank data. Phylogenetic analysis and genetic distance between species were evaluated using molecular evolutionary genetics analysis. FINDINGS: Thirteen isolates were sequenced, and nine species of cellulolytic bacteria dominated by the Bacillus genus were identified. These species exhibited an identity value of 97.77-100 percent when compared to data from GenBank, and B. velezensis was found to have a close relationship with B. amyloliquefaciens at a value of 0.002 percent. Interestingly, the non-rehabilitated mangrove areas had more bacterial species than the rehabilitated ones. Two Bacillus genus had different nucleotide bases, proving they were distinct species. CONCLUSION: Nine cellulolytic bacteria species were identified; the two closely interspecies genetic distance related were B. velezensis and B. amyloliquefaciens, whereas the farthest were Bacillus sp1. and Bacillus sp2. Small genetic distances of interspecies indicate a close relationship between species. In comparing the two sampling sites, the non-rehabilitated mangrove contains higher bacterial cellulolytic species than the rehabilitated and Bacillus-dominated site. The findings provide valuable insights into the diversity of cellulolytic bacteria in mangrove ecosystems. The abundance of bacterial species could serve as sources of cellulase enzymes with different characteristics, essential in an environmental aquatic management. [ABSTRACT FROM AUTHOR]

Recently, leaf litter has been used as compost or piled up and burned openly in most regions of Indonesia. This litter has the potential for its lignocellulosic components as the source of sugars. Also, the leave skeleton structure is promising for creative industrial purposes. Besides, termites (Macrotermes gilvus Hagen) can digest lignocellulosic biomass containing high fiber. In this research, termite extract contained lignocellulases and was used in the leaf litter pretreatment process for sugar preparation and leaf litter biosoftening. This study aimed to extract termite enzymes, identify, evaluate the activity of crude enzymes, and characterize the hydrolytic ability of enzymes to degrade lignocellulosic materials in three different leaf litters, i.e., Polyalthia longifolia (PL), Pterocarpus indicus (PI), and Filicium decipiens (FD). The leaf litter biosoftening process was performed in pulp removal for Annona muricata (AM) skeleton leaf crafts making. The results showed that M. gilvus Hagen extract exhibited high activity of endo-β-D-1,4-glucanase (CMCase), moderate activity of avicelase, β-D-1,4-mannanase, β-D-1,4-xylanase, and low β-D-1,4-glucosidase. The optimum pH of CMCase, β-D-1,4-mannanase, and β-D-1,4-glucosidase were 6.5, 5.0, and 6.0, respectively, while the optimum temperatures were 40 °C, 50 °C, and 55 °C, respectively. Cellulases from termite extracts were suitable pretreatment of leaf litter biomass, as evidenced by saccharification activity, with the highest saccharification activity in FD leaf litter. Enzymes were also successfully employed to help remove AM leaf pulp at the volume of 100 mL for 14 days, with the removal efficiency at 98.7%. [ABSTRACT FROM AUTHOR]

Indonesia has 25 species of month orchids and 10 of them are endemic to Indonesia. Plant Conservation Center (LIPI) conserved 15 species of orchids which means that it has been conserving as much as 23.44% of the orchids in the world (Rahayu, 2015). Orchid conservation efforts in Phalaenopsis amboinensis, both ex vitro and in vitro continue to be made in order to increase biodiversity. One of them is made by protoplast fusion approach that begins with the isolation of protoplast Phalaenopsis amboinensis. This study aimed to produce viable protoplast of Phalaenopsis amboinensis by developing procedure for mesophyll protoplast isolation. Protoplast is isolated from young orchid leaf. This experiment was conducted on six combinations of enzymes (Cellulase concentrations of 1%, 1.5%, 2% and macerozyme 1%, 1.5%) and two incubation in the dark (4 h and 6 h), so the total combinations become 12. The method of analysis used a completely randomized design. The viable protoplast result was evaluated. The result showed that the best achieved enzyme combination was Cellulase 2.0% + Macerozyme 1.0% and incubation time of 6 h; compared to other treatments of forming spherical protoplasts and chloroplasts it tends to clump together and solid. The number of protoplasts 1.1 × 106 and the percentage of viable protoplasts 83.88 %. [ABSTRACT FROM AUTHOR]

This study was conducted to characterize the cellulase enzymes produced by Streptomyces macrosporeus BB 32 and S. microspores KRC 21. D, which were isolated from Tanjung Pendam, Belitung Island, and from Cibodas Botanical Garden, Indonesia, respectively. The optimal activity of the enzymes was analyzed using parameters such as incubation time, pH, temperature, carboxymethylcellulose (CMC) concentration. The effect of the addition of some metal ions as activators or inhibitors was also analyzed spectrophotometrically at λ 540 nm. Results demonstrated that the activity of the cellulase enzymes of S. macrosporeus BB 32 and S. macrosporeus KRC 21 D reached the optimum level after 2 and 5 days of incubation and at pH values of 8.0 and 6.0, temperatures of 35 °C and 50 °C, and CMC concentrations of 1.75% and 2%, respectively. S. macrosporeus BB 32 cellulase was activated by the cations CuCl2, MgCl2, and ZnCl2 but inhibited by NaCl and CoCl2, reducing its activity. The cellulase of S. macrosporeus KRC 21.D was activated by the cation NaCl and by the divalent cations CoCl2, CuCl2, MgCl2, and ZnCl2. S. macrosporeus BB 32 was deposited at the Indonesian Culture Collection with the collection number InaCC A454. [ABSTRACT FROM AUTHOR]

Oil Palm Empty Fruit Bunch (OPEFB) is an abundant biomass resource in Indonesia, which contains 41.3 ~ 46.5% (w/w) of cellulose. This research examined the production of cellulase by the E. coli EgRK2 recombinant strain using an OPEFB substrate. The production of the enzyme was initially examined to identify optimum growth conditions, by observing the growth and activity of E. coli EgRK2 compared to its wild type. Our results showed that the optimum production time, pH and temperature of the recombinant growth and cellulase activity were achieved at 24 h, and at 7 and 40°C, respectively. Using these optimum conditions, the enzyme was produced, and experiments were carried out to examine the enzyme characteristics, produced from both strains, on hydrolysis of cellulose from OPEFB. Our results showed that the activity of the enzyme produced by the recombinant almost doubled compared to that of the wild type, although the optimum pH for both strains was pH 6. Higher activity was achieved by the recombinant compared to the wild type strain, and values were 1.905 and 1.366 U/mL, respectively. The optimum temperature for hydrolysis by cellulase occurred at 50°C for Bacillus sp. RK2, and 60°C for Bacillus sp. EgRK2. The Michaelis-Menten constant (Km) and maximum velocity (Vmax) for OPEFB degradation by E. coli EgRK2 were 0.26% and 1.750 μmol/mL/sec, which were significantly better values than those of the wild type. Control experiments for the degradation test using CMC also showed a better Vmax value for E. coli EgRK2 compared to the wild type, which is 2.543 and 1.605 μmol/mL/sec, respectively. [ABSTRACT FROM AUTHOR]

High contents of cellulose and hemicellulose of corncob waste makes it suitable as a raw material for sugar saccharification that can be used as sugar source for bioethanol fermentation. However, the presence of lignin inhibits the complete sugar conversion, necessitating pretreatment of the corncob material. Therefore, our study aimed to introduce a new pretreatment method for corncob to minimize lignin contents, hydrolyze it using an enzyme cocktail, and ferment it to bioethanol. Firstly, we studied pretreatment of corncob powder to minimize lignin interference using various reagents like 2% H 2 SO 4 , 2% NaOH, 2% H 2 SO 4 – 2% NaOH, and 15% NH 4 OH, which revealed that 15% NH 4 OH was the most efficient reagent. Then, several enzyme cocktails consisting of cellulase, xylanase, and xylose isomerase, isolated from microbes collected in Indonesia, in ratios of 1:1:1, 2:1:1, 1:2:1, and 1:1:2 were subjected to the pretreated corncob material. We found that hydrolysis with the enzyme cocktails produced significant amounts of reducing sugars, and 1:1:1 enzyme cocktail produced the highest amounts with amazing capability to ferment to bioethanol. • The presence of lignin inhibit the full sugar conversion, necessitating pretreatment of the corncob material. • The corncob powder was pretreated using 2% H 2 SO 4 , 2% NaOH, 2% H 2 SO 4 – 2% NaOH, and 15% NH 4 OH, revealed that treatment with 15% NH 4 OH was the best pretreatment to minimize lignin interference. • The enzyme cocktails consisting of cellulase, xylanase, and xylose isomerase were isolated from microbes collected in Indonesia which can hydrolyze corncob waste. • Enzyme cocktail produced the highest amount of reducing sugars, and can be fermented to bioethanol. [ABSTRACT FROM AUTHOR]