The new paper from our lab describes the development of a mini-repository of Polyhydroxyalkanoates producing marine bacteria from North Eastern Arabian Sea and Goa Coast. The study was led by Mr. Linu Balan and Dr. Sowmya P. Mohandas, and mentored by Prof. I. S. Bright Singh.

The authors isolated novel PHA-producing marine bacteria from the North Eastern Arabian Sea and the Goa coast. Vibrio alginolyticus MCCB 290 demonstrated the highest biomass yield and PHA production. A mini-repository of 347 PHA-producing marine bacteria belonging to diverse genera and species was established.

A new study from our lab demonstrated that microalgae-based functional feeds can transform aquaculture nutrition, offering sustainable alternatives to traditional diets. The study was led by Thasreefa K, and mentored by Dr. Valsamma Joseph.

Juvenile Silverado guppies (Poecilia reticulata) fed with the supplemented diet of chitosan-flocculated Picochlorum maculatum MACC3 showed significant improvements in growth, digestive enzyme activity, and immune response, with a 46.67% higher survival rate against Aeromonas salmonicida infection. Enhanced pigmentation and beneficial gut microbiome modulation further highlighted the efficacy of the supplemented diet. These findings underscore the potential of P. maculatum MACC3 as a sustainable feed ingredient, paving the way for environmentally friendly aquaculture practices.

The study led by Vinusree K.P. and mentored by Prof. I.S. Bright Singh focused on probiotic formulations for Macrobrachium rosenbergii post-larvae (PL). Their study has identified that feeding a combination of MY-1 and Enterotrophotic (ENT) probiotics for 20 days improve the growth and survival rates, even after being challenged with pathogenic Vibrio alginolyticus. The formulation enhanced the immune modulation and disease resistance as evident from immune-related gene expression analysis.
Their findings suggest that the combination of MY-1 and ENT probiotics can boost scampi seed production, and that immune gene expression analysis can be used as a potential tool for evaluating probiotic efficacy in aquaculture.

This study developed a novel in vitro cell culture system from Daphnia magna embryos to assess the toxic effects of Bisphenol A (BPA), a well-known environmental contaminant. The optimized culture system remained viable for up to two months, making it a stable model for toxicity testing. BPA exposure resulted in LC50 values of 52 µM and 20 µM at 24 and 48 hours, respectively, and induced significant oxidative stress, endocrine disruption, and DNA damage in exposed cells. Increased antioxidant enzyme activities (GSH, GPx, GST) and altered gene expression patterns (upregulation of hsp70, hsp90, gst, gpx, vtg1, and cyp4; downregulation of sod, cat, and ecr) were observed. Additionally, comet assays confirmed DNA damage, reinforcing the model’s relevance in ecotoxicological research. This work highlights the potential of in vitro Daphnia models as ethical and efficient alternatives for chemical toxicity assessments.

This study established a novel in vitro embryonic cell culture system from Daphnia magna to assess the cytotoxic and genotoxic effects of Bifenthrin (BIF), a commonly used pyrethroid insecticide with known environmental risks. Using Modified Schneider’s Insect Medium (MSIM), the cultured cells remained viable for over two months, providing a stable platform for toxicity studies. LC50 values for BIF were determined as 7.4 µg/mL and 4.3 µg/mL at 24 and 48 hours, respectively. BIF exposure induced oxidative stress, as evidenced by increased ROS levels and reduced antioxidant enzyme activities (GPx, GSH, GST), while co-treatment with N-acetylcysteine (NAC) alleviated these effects. Gene expression analysis revealed initial upregulation of stress-related (hsp70, hsp90) and antioxidant (Mn/ZnSod, cat) genes, followed by downregulation with prolonged exposure. Comet assays confirmed significant DNA damage, further demonstrating BIF’s genotoxicity. These findings underscore the relevance of Daphnia magna embryonic cell cultures as a promising alternative for in vitro toxicity testing, supporting environmentally safer pest control strategies.