Biotechnological potential of Bacillus sp. S26 for alleviation of abiotic and biotic stresses in vine.

Grapevine (Vitis spp.) is one of the most cultivated fruit plants in the world. Vineyard growers apply copper-based products in these crops to prevent fungal diseases, generating worries about Cu contamination in soils and food. In this context, this study identifies prokaryotic communities associated with grapevine plants grown under different levels of Cu-contaminated soils. Moreover, the study isolates new bacteria to improve Cu resistance in plants. Soil Cu content correlated inversely with operational taxonomic units (OTUs) belonging to the groups Acidobacteria (SubGroup 2), Latescibacteria, Pedosphaeraceae, and Candidatus Udaeobacter. A total of 14 new bacterial isolates were obtained from copper-contaminated soils. These isolates produced Indolic Compounds (IC) in a range of 25 to 96 µg mL- 1, highlighting bacterial strains S20 and S26 as the highest producers. These new bacteria also produced siderophores, highlighting strains S19 and S26, which removed 58 and 59% of Fe ions from the CAS complex, respectively. From the in vitro antagonistic activity against Colletotrichum spp. strains, the authors identified some bacterial strains that inhibited phytopathogen growth. Bacterial strain Bacillus sp. S26 was chosen for inoculation experiments in grapevine plants. This bacterial isolate improved the growth of grapevine plants in Cu-contaminated soils. However, growth promotion did not occur in unstressed plants. More studies are necessary for developing a new bioinoculant containing S26 cells aiming to reduce biotic and abiotic stresses in grapevine.

Feeding laying hens with lactobacilli improves internal egg quality and animal health.

Feeding animals with lactobacilli strains is a biotechnological strategy to improve production, food quality, and animal health. Thus, this study aimed to select new lactic acid bacteria (LAB) able to improve laying hens health and egg production. Forty Bovans White layers (two days old) were randomly divided into four experimental groups that receive an oral gavage with saline solution (control group) or with one of the three lactobacilli selected (KEG3, TBB10, and KMG127) by their antagonistic activity against the foodborne pathogen Bacillus cereus GGD_EGG01. 16 S rRNA sequencing identified KEG3 as Lentilactobacillus sp., and TBB10 and KMG127 as Lactiplantibacillus sp. The data showed that feeding birds with LAB increased weight uniformity and improved the internal quality of the eggs (high yolk index and Haugh unit) compared with the control group (p < 0.05). Beta-diversity analysis showed that LAB supplementation modifies the cecal microbiota of laying hens. The prokaryotic families Bacteroidaceae, Ruminococcaceae, Rikenellaceae, and Lactobacillaceae were most important to the total dissimilarity of the cecal microbial community (calculated by SIMPER test). At end of in vivo experiments, it was possible to conclude that the feed of laying hens with Lentilactobacillus sp. TBB10 and Lentilactobacillus sp. KEG3 can be an important biotechnological tool for improving food quality and animal health.

Osmotin1 is involved in rice resistance to Schizotetranychus oryzae (Acari: Tetranychidae) infestation.

BACKGROUND: Rice is one of the most consumed cereals in the world. Productivity losses are caused by different biotic stresses. One of the most common is the phytophagous mite Schizotetranychus oryzae Rossi de Simons (Acari: Tetranychidae), which inhibits plant development and seed production. The identification of plant defense proteins is important for a better understanding of the mite-plant interaction. We previously detected a high expression of Osmotin1 protein in mite-resistant rice cultivars, under infested conditions, suggesting it could be involved in plant defense against mite attack. We therefore aimed to evaluate the responses of three rice lines overexpressing Osmotin1 (OSM1-OE) and three lines lacking the Osmotin1 gene (osm1-ko) to mite attack. RESULTS: The numbers of individuals (adults, immature stages, and eggs) were significantly lower in OSM1-OE lines than those in wild-type (WT) plants. On the other hand, the osm1-ko lines showed larger numbers of mites per leaf than WT plants. When plants reached the full maturity stage, two out of the three infested OSM1-OE lines presented lower plant height than WT, while the three osm1-ko lines (infested or not) presented higher plant height than WT. The reduction in seed number caused by mite infestation was lower in OSM1-OE lines (12-19%) than in WT plants (34%), while osm1-ko lines presented higher reduction (24-54%) in seed number than WT plants (13%). CONCLUSION: These data suggest that Osmotin1 is involved in rice resistance to S. oryzae infestation. This is the first work showing increased plant resistance to herbivory overexpressing an Osmotin gene. © 2023 Society of Chemical Industry.

Use of biotechnological approaches to add value to rice hulls.

One of the most common agricultural wastes generated in rice producing countries, rice hull (RH) is considered an environmental problem due to increased rice production and RH accumulation, especially because natural degradation in the environment is very difficult and time-consuming. Currently, RH is mostly used as bed for broiler chickens or burned for energy generation, two processes that prevent environmental accumulation in a sustainable way, without adding value to the RH. To diversificate its use and effectively add some value to the RH, a pretreatment is frequently needed, allowing the application of several biotechnological approaches. In this review, we gather information about biotechnological uses of crude and processed RH, including their use as fertilizers, filler material in natural rubber and incorporation in cement for civil construction purposes, along with their use in processes as silica extraction and adsorption/removal of environmental contaminants as heavy metals and dyes. Finally, we critically evaluate the data published in the literature, and based on our own findings, we point future directions related to RH biodegradation and further methane production.