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The high susceptibility to deterioration and diseases during the supply chain and/or during the storage of fresh products is a problem in the industry, and edible films are proposed as efficient methods to preserve its quality. The objective was to obtain and characterize silver nanoparticles (AgNPs) and determine their effect on optical, barrier and mechanical properties of alginate-based films. The alginate was extracted from Sargassum fluitans. AgNPs were obtained by green synthesis using Gliricidia sepium. The UV–Vis and dynamic light scattering (DLS) were used to characterize the AgNPs. The antifungal activity of AgNPs was investigated using several fungal strains. Films were formulated by using 2 and 3% alginate, as well as 0, 1, and 2 mg of AgNPs per mL of formulation, with glycerol as a plasticizer. A randomized experimental design was used to test the effect to alginate and the AgNPs concentrations. The results were analyzed by an ANOVA test (p

Tofu is one of the main foods made with soybeans. The aim of this work was to evaluate the effect of L. plantarum and L. fermentum on the volatile compounds and sensorial profile of fermented tofu during ripening. The soy milk was fermented separately with two native strains (L. plantarum or L. fermentum) until reaching a pH of 5.5, and the fermented tofu was obtained. The tofu obtained by acidification with lactic acid was used as a control and was characterized by microbial survival (L. plantarum, L. fermentum, and P. freudenreichii) for 0, 20, and 40 days of storage at 15 °C. Moreover, the lactic and acetic acid content was determined by high-performance liquid chromatography (HPLC), and the volatile compounds were evaluated by gas. Chromatography-mass spectrometry (GC-MS). The results were analyzed by an ANOVA test (P 0.05). After storage, the lactic acid bacteria (LAB) survived in the fermented tofu at a concentration higher than 8.0 log CFU/g after 40 days of storage. The shelf life of fermented tofu obtained by acidification was fewer than 20 days because of the presence of fungi and yeasts. The hexanal content was reduced by approximately 96% (P 0.05) in the tofu obtained by fermentation compared with the control. This process for fermented tofu production employing two native strains could be used for industrial purposes.

Agronomic biofortification is a process used to increase the concentration of essential elements in plants through fertilization and thus improve their nutritional quality. Increasing the content of Zn+2 in Stevia rebaudiana plants would imply adding value to the crop. The use of ZnO phytonanoparticles, in addition to increasing the content of Zn+2, can also generate an inductor effect that promotes the synthesis of metabolites of commercial interest. This study reports the effect of fertilization with ZnO phytonanoparticles on morphometric parameters of S. rebaudiana plants and the content of Zn+2, stevioside, rebaudioside A, total phenols, flavonoids and the antiradical activity of leaf extracts. Biofortification was carried out in a hydroponic culture using peat moss/agrolite as a support under a completely random experimental design. The green ZnO nanoparticles were added via root at different concentrations. The physiological and morphometric parameters of the plant were not affected with respect to the control by the use of phytonanoparticles. The biofortification of S. rebaudiana with ZnO phytonanoparticles at a concentration of 75 mg/L enhanced zinc content up to 406.8% with respect to the control. The total phenols (60.5%) and flavonoids (87.8%) were also increased without having a negative effect on plant growth. The biosynthetic pathway of steviol glycosides was not affected.

The "El Chichón" crater-lake in Mexico is a thermo-acidic environment whose microorganisms have been scarcely studied. In this study, we surveyed the prokaryotic communities by amplicon sequencing of the 16S rRNA gene considering samples of sediment and water collected within a pH/temperature gradient (pH 1.9-5.1, 38-89 °C). Further, we interpreted these results within a physicochemical context. The composition of the microbial assemblage differed significantly between the sediments and water. Sediment communities were different in the site with the highest temperature and lower pH value compared to the other ones sampled, while those in the water were relatively similar at all points. Most of the genera found were related to Alicyclobacillus, Acinetobacter, Bacillus, Mesoaciditoga, Methanothermobacter, Desulfitobacterium, Therminicanus, Kyrpidia, Paenibacillus, Thermoanaerobacterium, and Gelria. Some of these genera are known by their thermo-acidic tolerant capacities with flexible metabolisms to use diverse electron donor/acceptors (S or Fe), while others are thermo(acid)philes that mainly occur in the most extreme sites of the lake. These results show the presence of a microbial community adapted to the changing conditions of a very dynamic crater-lake, that include chemoorganotrophs and chemolithotrophs.

Agave grijalvensis (B. Ullrich) was inoculated with Glomus fasciculatum (Thaxter sensu Gerd.) Gerd. and Trappe) and fertilized with different amounts of phosphorus (P) during plant development. Mycorrhizal colonization, fructan accumulation and fructosyltransferases enzymatic activities were determined. Glomus fasciculatum increased fresh weight of A. grijalvensis, the number of leaves, root length and fructan concentrations in stems and leaves. Phosphorus increased sucrose content, but reduced glucose and fructose concentrations in both leaves and stems. Activities of 1-fructosyltransferase (1-SST) (EC 2.4.1.99) and β-fructan-1-fructosyltransferase (1-FFT) (EC 2.4.1.100) were determined and explained due to different levels of fructans detected in A. grijalvensis plantlets.

Basil (Ocimum basilicum L.) is a hyperaccumulative herbaceous plant that has the ability to grow in contaminated soils and is believed to harbor a wide variety of bacterial species resistant to recalcitrant toxic chemical compounds. The objective of this work was to evaluate the potential for removal of decaclorobiphenyl PCB-209 by bacteria associated with the O. basilicum plant. A total of 34 endophytes and 52 strains from the rhizosphere of this plant were isolated using selective culture media. The adaptive capacity of the bacteria in phenol and Arochlor 1242 was initially determined and then a set of bacteria was selected and their removal potential of decachlorobiphenyl PCB-209 was evaluated. The phylogenetic analysis of 16S rRNA gene grouped to the O. basilicum isolates within bacterial genera Acinetobacter, Bacillus, Lysinibacillus, Novosphingobium, Pseudomonas, Rhizobium, Sphingobium, Stenotrophomonas, and Terribacillus as well as bacterial strains Pseudomonas taiwanensis BS-1, Rhizobium nepotum BS-2, Terribacillus sacharophilus BS-3, Stenotrophomonas rhizophila BS-4, Bacillus arybhattai BS-5, and Lysinibacillus macroides BS-6 showed the ability to adapt and use phenol and Arochlor 1242 as source of C. The strains BS-4 isolated from the root of the plant showed a higher potential from the removal of the PCB-209 (390.75 mg L−1) at an initial concentration of 500 mg L−1 and also had the ability to synthesize biosurfactant (EI = 60%) compared to the other strains evaluated. The diversity of bacteria associated to O. basilicum had biological qualities that may contribute to their adaptation and proliferation in an environment contaminated by PCB and be used efficiently as bioremediation to relieve agricultural soils contaminated by persistent organic compounds.

The aim of this work was to develop and evaluate the effect of an edible coating produced with protein isolate and gum from the Cajanus cajan seed to be applied to strawberries (Fragaria spp.). The films were formulated using 1 and 2% gum, and 5 and 10% protein isolate, as well as glycerol (2%) as a plasticizer. The formulated films were evaluated in terms of water vapor permeability (WVP), opacity, color, scanning electron microscopy, and texture. Once the ideal formulation with sufficiently low WVP and opacity was selected, it was applied to the strawberries, which were evaluated in terms of mass loss, color, firmness, acidity, pH, soluble solids, anthocyanin content, vitamin C content, and acceptability degree by an untrained consumer panel. Results showed that film made from 5% of protein isolate and 1% of gum had the lowest WVP of all treatments. Applied to strawberries, the coating resulted in a reduction of the total soluble solid content, the consumption of citric acid, and the mass loss of coated with respect to uncoated strawberries after 10 days of storage at 5 °C, without causing sensorial changes.

The aim of this protocol was for Bonellia macrocarpa hairy root establishment and bonediol production in transformed root cultures. Cotyledons, hypocotyls and roots were used as explants for hairy root induction. Fluorescence microscopy was used for detected tandem dimer of the tomato protein (TDT). A PCR analysis for rolC was used to confirm the presence of these genes. Identification and quantification of bonediol was made for HPLC. Hypocotyls showed greater transformation efficiency (25%). Fluorescence microscopy and PCR analysis confirm genetic transformation. Bonedio production was higher in hairy roots than in complete plants.

Cotton production in the Mexicali valley is adversely affected by wilt and root rot disease associated with Fusarium species. Therefore, the aim of this study was to identify the antifungal activity and presence of lipopeptides genes in Bacillus subtilis strain Bs-Cach isolated from the rhizosphere of the cachanilla (Pluchea sericea). The dual culture technique was conducted to test antifungal effect of the Bs-Cach on the growth of Fusarium solani strains (ICA-3 and ICA-4, respectively), and the presence of iturin (ItuA), surfactin (SrfC), and fengycin (FenD) (lipopeptides genes), was evaluated by PCR analysis. The results obtained revealed that Bs-Cach inhibited the growth of F. solani ICA-3 and ICA-4, with a range of percentage inhibition from 50 and 52 after 120 h, respectively. On the other hand, our result of the PCR amplification of the lipopeptide genes from DNA of Bs-Cach showed solely the presence of iturin but not surfactin and fengycin genes. The analysis of sequence ituA present in Bs-Cach showed 84 % identity with iturin A synthetase of different B. subtilis strains. This study showed that B. subtilis Bs-Cach strain has the ability of inhibiting F. solani strains by at least one mechanism, the lipopeptide synthesis. This result turns Bs-Cach into a potential alternative for the biological control of F. solani. Nevertheless, this study was conducted under in vitro conditions, and further studies are required to investigate whether these results hold true under field conditions.

This paper reports on the optimum concentrations of naphthalene acetic acid (NAA) and 6-benzyladenine (BA) to stimulate callus growth and NAA; kinetin and silver nitrate (AgNO3) for callus redifferentiation in Dianthus caryophyllus L. Meristems were excised and placed in MS medium with 30 g l−1 sucrose and 9.0 μM 2,4-d. Callus clusters were transferred to MS medium containing NAA (0, 1.7, 3.3, and 5.0 μM) and BA (0, 1.7, 3.3, and 5.0 μM) for proliferation and to MS medium with 30 g l−1 sucrose, 2.5 g l−1 phytagel, kinetin (0, 33, and 66 μM); NAA (0, 7.95, and 15.9 μM) and AgNO3 (0, 23.54 and 47.08 μM) for shoot and root induction. Treatments were applied according to a Box–Behnken design. After callus growth and redifferentiation, plants were incubated in the greenhouse at 18 ± 2°C for 4 wk and at 20–26°C for 4 wk. Finally, plants were changed to near-commercial greenhouse conditions with different day (30–35°C) and night (16–24°C) temperatures. Results showed better callus growth at higher NAA concentrations. A maximum callus weight was found with 5.0 μM NAA but without BA. A maximum of 78% calluses with shoots was obtained with 15.9 μM NAA, 47.08 μM AgNO3, and 0.74 μM kinetin and 58% with roots with 15.7 μM NAA and 47.08 μM AgNO3, but without kinetin. The shoots obtained showed little hyperhydricity. Vigorous plants were obtained after gradual acclimatization with an 80% survival rate under nursery conditions.

This study aimed to evaluate the removal of polychlorinated biphenyls, with a vermicomposting system, using the following as components: the earthworm Eisenia fetida, peat moss and rabbit excrement and a compound called decachlorobiphenyl, for a period of 91 days under non-sterile conditions. The results obtained were a removal of decachlorobiphenyl 79.6 % with an initial concentration of 100 mg L−1, 89.7 % with 150 mg L−1 and 95.38 % with 200 mg L−1; the earthworms bioaccumulated less than 5 mg L−1 in all concentrations of decachlorobiphenyl analysed without apparent toxic effect. Weight gain was observed in earthworms that assimilated contaminant during vermicomposting, as the number of cocoons produced in contrast to the control in which both the weight and the number of cocoons were lower. To our knowledge, this is the first study which suggests that vermicomposting may be a suitable mechanism for removal of decachlorobiphenyl with high recalcitrance from contaminated sediment or soils.

The activities of sucrose-phosphate synthase (SPS), sucrose synthase (SUSY), neutral invertase (NI) and soluble acid invertase (SAI) regulates sucrose activity in sugarcane were studied. Micropropagated sugarcane plants were obtained from callus cultures of four Mexican commercially available sugarcane varieties characterized by differences in sugar production, and activities of SPS, SUSY, NI, SAI and concentrations of sucrose were monitored in the sugarcane stem. The results indicated that sucrose accumulation was positively and significantly related to an increase in activity of SPS and SUSY and negatively to a reduction in activity of SAI and NI (P