Asit Ranjan Ghosh

Sudaarsan Aruna Senthil Kumar and Asit Ranjan Ghosh. J. Microbiol. Biotechnol. 2026;36:1-13. https://doi.org/10.4014/jmb.2604.04005

Conjugated linoleic acid (CLA) is a group of positional and geometric isomers widely admired for its anti-inflammatory and anti-carcinogenic effects. Enzymes responsible for bioconverting linoleic acid (LA) into CLA are diverse, found in a wide range of microorganisms from lactic acid bacteria (LAB) to non-lactic acid bacteria (non-LAB). Various LAB and non-LAB strains show promising results in CLA production. Enzymes such as linoleate isomerase (LAI), Myosin cross-reactive antigen (MCRA), and oleate hydratase, involved in CLA production, are also diverse in nature. They originate from various sources and have demonstrated potential to biohydrogenate LA and other similar substrates. Comparative analysis of substrate–enzyme dynamics revealed substantial structural conservation alongside functional divergence among various biohyrogenating enzyme-associated pathways, suggesting evolutionary adaptation toward fatty acid detoxification and membrane homeostasis. Furthermore, environmental and physiological factors such as substrate availability, oxygenation, pH, temperature, and growth phase were found to significantly influence CLA biosynthesis. Despite considerable advances, several mechanistic aspects of enzyme cooperation, pathway regulation, and evolutionary relationships remain unresolved. This article critically examines various aspects of substrate–enzyme dynamics, their ecology, evolution, and molecular regulation. It aims to bridge the knowledge gap in catalytic mechanisms and regulation while summarizing available information on various enzymes responsible for the bioconversion of LA to CLA, implicating fundamental microbiology and biotechnology.

Pediococcus pentosaceus GS4 is a gram-positive potential probiotic strain isolated from Indian food, Khadi. The probiotic potential of GS4 is evidenced by published research works in vitro and in mice. Here, we report the 1.6 Mb assembly and annotation of the whole-genome sequence of P. pentosaceus GS4.

Background: Microencapsulated Pediococcus pentosaceus GS4 (MTCC 12683) with prebiotics and chitosan coating can be used in food functional products, enhancing shelf life and restoring probiotic properties. Objective: This study aimed to analyze the effects of inulin (I) fructooligosaccharide (FOS) and chitosan coating in microencapsulation of probiotic strain P. pentosaceus GS4 survivability in simulated gastrointestinal (GI) conditions and at different storage conditions. Methods: To enhance the stable viability of probiotic P. pentosaceus, GS4, inulin, and FOS were separately combined into alginate (Alg) following chitosan (C) coating during the process of microencapsulation. Encapsulation efficiency, morphological characterization, and cell survival of different microbeads were evaluated before and after exposure to simulated GI conditions at different storage conditions. Results: Alginate-inulin-FOS combined chitosan coated (Alg/I/FOS/C) microbeads showed higher viability than other groups. Chitosan-coated beads had increased diameter (2.52- 2.71 mm) in comparison to uncoated beads (1.98- 2.42 mm). On successive challenges through simulated GI conditions, microencapsulated probiotics demonstrated higher viable cells than control cells (P 4°C > room temperature. Conclusion: In conclusion, Alg/I/FOS/C beads stored at -20°C maintained stable probiotic viability and are found to be suitable for food technological applications.

Conjugated Linoleic Acid (CLA) is a polyunsaturated dietary fatty acid. Probiotics can biohydrogenate CLA with multiple health benefits, especially in cancer treatment. In vitro, in vivo, and clinical studies have confirmed CLA isomers to possess anti-cancer activity. CLA has demonstrated its potential as an alternative treatment for cancer and also used as an adjuvant to reduce the side effects of existing treatment methods. The mechanism of the anticancer activity of CLA is still not clear; however, it may involve intervention with the cell cycle and modulation of gene expression. A greater potential of CLA for cancer treatment has been supported by more and more clinical trials to evaluate its potential. Some advanced technologies are in progress to overcome the flaws of current methods and enhance the microbial production of CLA. In conclusion, nutritional enrichment as a functional food and direct consumption of CLA may contribute to cancer management.

Cancer remains a multifactorial disease with an increased mortality rate around the world for the past several decades. Despite advancements in treatment strategies, lower survival rates, drug-associated side effects, and drug resistance create a need for novel anticancer agents. Ample evidence shows that imbalances in the gut microbiota are associated with the formation of cancer and its progression. Altering the gut microbiota via probiotics and their metabolites has gained attention among the research community as an alternative therapy to treat cancer. Probiotics exhibit health benefits as well as modulate the immunological and cellular responses in the host. Apart from probiotics, their secreted products like bacteriocins, exopolysaccharides, short-chain fatty acids, conjugated linoleic acid, peptidoglycan, and other metabolites are found to possess anticancer activity. The beneficiary role of these postbiotic compounds is widely studied for characterizing their mechanism and mode of action that reduces cancer growth. The present review mainly focuses on the postbiotic components that are employed against cancer with their reported mechanism of action. It also describes recent research works carried out so far with specific strain and anticancer activity of derived compounds both in vitro and in vivo, validating that the probiotic approach would pave an alternative way to reduce the burden of cancer.