Polyunsaturated fatty acids (PUFAs), which contain two or more double bonds in their backbone, are the focus of intensive global research, because of their nutritional value, medicinal applications, and potential use as biofuel. However, the ability to produce these economically important compounds is limited, because it is both expensive and technically challenging to separate omega-3 polyunsaturated fatty acids (ω-3 PUFAs) from natural oils. Although the biosynthetic pathways of some plant and microalgal ω-3 PUFAs have been deciphered, current understanding of the correlation between fatty acid desaturase content and fatty acid synthesis in Synechocystis sp. PCC6803 is incomplete. We constructed a series of homologous vectors for the endogenous and exogenous expression of Δ6 and Δ15 fatty acid desaturases under the control of the photosynthesis psbA2 promoter in transgenic Synechocystis sp. PCC6803. We generated six homologous recombinants, harboring various fatty acid desaturase genes from Synechocystis sp. PCC6803, Gibberella fujikuroi and Mortierella alpina. These lines produced up to 8.9 mg/l of α-linolenic acid (ALA) and 4.1 mg/l of stearidonic acid (SDA), which are more than six times the corresponding wild-type levels, at 20°C and 30°C. Thus, transgenic expression of Δ6 and Δ15 fatty acid desaturases enhances the accumulation of specific ω-3 PUFAs in Synechocystis sp. PCC6803. In the blue-green alga Synechocystis sp. PCC6803, overexpression of endogenous and exogenous genes encoding PUFA desaturases markedly increased accumulation of ALA and SDA and decreased accumulation of linoleic acid and γ-linolenic acid. This study lays the foundation for increasing the fatty acid content of cyanobacteria and, ultimately, for producing nutritional and medicinal products with high levels of essential ω-3 PUFAs.

Cyanobacteria have evolved various strategies to sense and adapt to biotic and abiotic stresses including active movement. Motility in cyanobacteria utilizing the type IV pili (TFP) is useful to cope with changing environmental conditions. The model cyanobacterium Synechocystis sp. PCC 6803 (hereafter named Synechocystis) exhibits motility via TFP called thick pili, and uses it to seek out favorable light/nutrition or escape from unfavorable conditions. Recently, a number of studies on Synechocystis thick pili have been undertaken. Molecular approaches support the role of the pilin in motility, cell adhesion, metal utilization, and natural competence in Synechocystis. This review summarizes the most recent studies on the function of thick pili as well as their formation and regulation in this cyanobacterium.

In this study, we utilised palm kernel cake as a substrate and fermented it with a composite of bacteria (Pediococcus pentosaceus CGMCC No. 27203 and Lactobacillus plantarum CGMCC No. 27202) and enzymes. We conducted a trial with twenty-four cattle, randomly divided into two groups of twelve cattle each. The control group (CON) was fed the standard farm diet, whereas the treatment group (PKC) received a diet with 3% of soyabean replaced by fermented palm kernel cake. The trial lasted for six weeks. The results showed no significant differences in growth performance between the PKC and CON groups. The abundance of Firmicutes, Bacteroidetes, Proteobacteria, and Spirochaetes was significantly higher in the PKC group than in the CON group. At the genus level, the abundances of Anaeroplasma, norank_f__Bacteroidales_UCG-001, norank_f__Absconditabacteriales_SR1, norank_f__p-251-o5, Prevotellaceae_NK3B31_group, Prevotellaceae_UCG-001, Prevotellaceae_UCG-004, and Treponema significantly increased in the PKC group. Lipid digestion and absorption pathways were significantly enriched in the PKC group. The results indicate that adding fermented palm kernel cake to the diet can increase the abundance of Bacteroidetes and Fibrobacteres in the rumen of beef cattle, enhancing the ability of the PKC group to degrade protein, carbohydrates, and fibrous materials in the feed, thereby improving the feed utilisation efficiency in beef cattle. Adding fermented palm kernel cake to the diet improved carbohydrate metabolism, metabolism of cofactors and vitamins, and nucleotide metabolism. Correlation analysis between the rumen microbiota and metabolic pathways showed that Prevotellaceae_UCG-001 and Prevotellaceae_UCG-003 were positively correlated with amino acid metabolism, Rikenellaceae_RC9_gut_group and Succiniclasticum were positively correlated with metabolism of cofactors and vitamins, and Prevotella and Ruminococcus were positively correlated with nucleotide metabolism. These findings elucidate the differences in rumen microbiota when fermented palm kernel cake is added to the diet, providing a theoretical basis for the application of fermented palm kernel cake in the diet of beef cattle.

Probiotics are beneficial to humans and animals and often used for regulating immunity, intestinal microbiota balance, and animal growth performance. Donkey husbandry has boomed in China in recent years and there is an urgent need for probiotics effective for improving donkey health. However, studies on potential probiotic strains isolated from donkeys are scarce. This project aimed to screen LAB strains from donkey feces, detect their antimicrobial activity and evaluate their probiotic characteristics in vitro. Thirteen LAB isolates showed different degrees of antimicrobial activity against four indicator bacteria: three common pathogens (Escherichia coli, Staphylococcus aureus, and Salmonella typhimurium) and one pathogen restricted to equines (Salmonella. abortus equi), eight of which could inhibit all four pathogens. Seven isolates showed higher tolerance to low pH and bile salts, with >50% and >60% survival rates, respectively. Five of them had more than 50% survival rate to artificial gastric and intestinal fluids. Only three isolates possessed good properties, with >40% auto-aggregation, >40% hydrophobicity, and high co-aggregation with the indicator pathogens. An L9 isolate, identified as Ligilactobacillus salivarius, was sensitive to most antibiotics tested. Overall, these results indicate that the L. salivarius L9 isolate meets the requirements of the probiotics selection criteria in vitro and can potentially be developed as a probiotic for donkeys.

We demonstrated the role of natural probiotics 3L, 3 Lactobacilli, in the establishment of a strong and sustainable beneficial healthy gut flora, after chemotherapy through experimental results through in vivo model. Using rat CTX model (immunosuppression induced by cyclophosphamide), we suggested some new adjuvant to chemotherapy as drugs + lactobacillus treament. Further, we proposed a new probiotic formulation (L. acidophilus + L. casei + L. plantarum) to be explored in the prevention of health condition loss by alteration of the general immune system, in numerous studies that reported the use of probiotics involving Lactobacillus in the post-chemo or post-surgical procedures. Here, in our study, Illumina MiSeq sequencing was used to generate sequencing data from microbial genomic DNA libraries, which is appreciable to check for the effects of 3L on bacteria. Microbiome analysis, phylogenetic and classification reports, community data have supported the experiments and the results where 3L had strong beneficial effects on the microbiome. Further, the influence on specific metabolic pathways are assisted in deriving the conclusion of the study (use of 3L for cancer therapy) to the mode of action, mechanistically by correcting microbiota composition and enhancing specific gut metabolic functions.