ISRP | IJAIDR

Latest Articles | 2026 | Vol 06

Microbial Cell Factories in Bioprocessing Engineering: Metabolic Engineering for Sustainable Biomanufacturing

by Subiksha Periyasamy and Berciyal Golda Peter*

Abstract : Microbial cell factories—microorganisms reprogrammed to convert renewable feedstocks into value-added molecules—have become central to modern bioprocessing engineering. Advances in systems and synthetic biology, genome editing and high-throughput screening now permit the rational design of strains that manufacture fuels, bulk and fine chemicals, pharmaceuticals and materials that were previously accessible only through petrochemical routes. This review outlines the conceptual framework and enabling technologies of microbial cell factory development, including host (chassis) selection, pathway construction and balancing, flux optimisation through metabolic and regulatory engineering, and the iterative design–build–test–learn cycle. Landmark achievements are highlighted, among them the semi-synthetic production of the antimalarial precursor artemisinic acid in Saccharomyces cerevisiae, the commercial fermentative manufacture of 1,3-propanediol and 1,4-butanediol, and gas fermentation of carbon-monoxideand carbon-dioxide-rich streams by acetogenic bacteria. The expanding toolbox of CRISPR-based genome editing, dynamic biosensor-driven control, genome-scale metabolic modelling and machine learning is discussed as a driver of predictable strain engineering. Attention is also given to nonconventional hosts such as Yarrowia lipolytica and Pichia pastoris, and to the bioprocess considerations—medium design, fermentation mode, oxygen transfer, scale-up and downstream recovery—that decide whether a promising strain becomes an economically viable process. Persistent challenges, including metabolic burden, redox and cofactor imbalance, modest product titres, and the gap between laboratory and industrial performance, are examined alongside emerging solutions. Microbial cell factories are positioned as a cornerstone technology for a sustainable, circular bioeconomy.

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Development and Functional Characterization of a Plant-Based Symbiotic Beverage Enriched with Lactobacillus plantarum

by Selladurai K and Subana suyambumani*

Abstract : The growing demand for plant-based functional foods has encouraged the development of non-dairy probiotic beverages with added health benefits. This study focuses on the formulation and evaluation of a symbiotic beverage prepared using Lactobacillus plantarum and selected herbal ingredients including banana stem, aloe vera, amla, and honey. Fresh extracts were obtained from the plant materials, blended in suitable proportions, and subjected to mild heat treatment. The probiotic culture was incorporated under sterile conditions, followed by fermentation at 37°C for 24 hours. The prepared beverage was analyzed for physicochemical properties, antioxidant potential, anti-inflammatory activity, and phytochemical constituents. The fermented product exhibited an acidic pH of 3.7, which supports probiotic stability and inhibits undesirable microbial growth. With an IC₅₀ value of 20.38 µg/mL, the antioxidant activity, as measured by the DPPH assay, demonstrated efficient free radical scavenging. Anti-inflammatory activity assessed through RBC membrane stabilization indicated approximately 50% protection. The presence of important bioactive substances such as flavonoids, phenols, alkaloids, and steroids was verified by phytochemical screening. Overall, the developed beverage demonstrates promising functional and therapeutic properties. The study highlights the potential of combining probiotics with plant-based ingredients to produce a health-promoting symbiotic drink suitable for improving digestive health

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Efficacy of Biogenically Synthesized ZnO Nanoparticles by Hyptis suaveolens Leaf Extract against Cowpea Weevil (Callosobruchus maculatus) for Pesticidal Activity

by Ponmani S*, Poornima G and Chindhana DS

Abstract : This study reports the green synthesis and multifunctional evaluation of zinc oxide nanoparticles (ZnO NPs) using Hyptis suaveolens leaf extract. Fresh leaves were shade-dried, pulverized, and extracted to prepare the bio-reducing precursor, with zinc sulfate used as the metallic source. A color shift from deep green to pale yellow confirmed nanoparticle formation. The synthesized ZnO NPs were characterized by XRD, SEM, EDX, and FTIR, revealing crystalline, spherical particles stabilized by phytochemicals. Antibacterial assays demonstrated strong inhibitory activity against Bacillus subtilis, Pseudomonas aeruginosa, and Enterococcus faecalis, with Gram-positive strains showing higher sensitivity. Pesticidal bioassays against Callosobruchus maculatus showed dose-dependent mortality, reduced adult emergence, seed damage, and weight loss, along with enhanced seed protection. At higher concentrations (750–1050 ppm), ZnO NPs achieved complete adult suppression; however, 1050 ppm slightly reduced seed germination. These findings highlight H. suaveolens-mediated ZnO NPs as eco-friendly, dual-functional agents for sustainable pest and microbial management in agriculture.

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Evaluation of Environmental Microbial Contamination and Effectiveness of Cleaning Protocols in Controlled Manufacturing Environments

by Palani Velan R*, Karuppusamy R, Priyadharshini S, Srividhya K, Ramya S and Prakash Balu3*

Abstract : Environmental microbial monitoring program is an essential protocol to ensuring the safety, and quality of food-grade and cosmetic-grade products derived from plant-based extracts. This study uses air and surface sampling techniques to evaluate the microbial contamination risks in the product contact surface areas. The data collected through settle plates, manual swabs, and ATP tester/Luminometer, highlights the microbial risk assessment and implementation of hygiene protocols in critical areas. This study highlights best practices and improvement measures for contamination control by classifying clean room zones and utilizing quantitative microbial risk assessment models.

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