Scylla serrata generally known as the mud crab is a common inhabitant of estuarine waters and mangrove sediments in the Indo-Pacific region. Being a dweller of estuarine habitats and mangrove sediments along with having diverse feeding habits, it is an appropriate candidate for a bioprospecting study. The bacteria associated with its gut were isolated and screened for industrially important enzymes such as amylase, cellulase, chitinase and ligninase. The exopolysaccharide production, calcium carbonate dissolution and bioluminescence properties were also studied. Multiple distinctive bacteria that possess these characters were isolated. In this study we report for the first time, the presence of bacterium Macrococcus caseolyticus in the gut of the mud crab inhabiting an estuary of the river Mandovi in North Goa, India. Confirmatory identification studies were conducted by means of biochemical and molecular analysis and supplemented with data from scanning electron microscopy. We focus here on isolating and screening the gut microflora of the mud crab, S. serrata to understand its true industrial potential. We hope that the presence of bacterial isolates that have massive biotechnological applications as demonstrated in this study, can attract attention leading to investigations on the scantly studied gut microbiomes of marine crabs.

Mud crab, bioprospecting, enzymes, gut microflora, Macrococcus caseolyticus