Hydrolytic Exoenzymes Produced by Bacteria Isolated and Identified From the Gastrointestinal Tract of Bombay Duck

Abstract

Bacteria producing hydrolytic exoenzymes are of great importance considering their contribution to the host metabolism as well as for their various applications in industrial bioprocesses. In this work hydrolytic capacity of bacteria isolated from the gastrointestinal tract of Bombay duck (Harpadon nehereus) was analyzed and the enzyme-producing bacteria were genetically characterized. A total of twenty gutassociated bacteria, classified into seventeen different species, were isolated and screened for the production of protease, lipase, pectinase, cellulase and amylase enzymes. It was found that thirteen of the isolates could produce at least one of these hydrolytic enzymes among which protease was the most common enzyme detected in ten isolates; lipase in nine, pectinase in four, and cellulase and amylase in one isolate each. This enzymatic array strongly correlated to the previously reported eating behavior of Bombay duck. 16S rRNA gene sequence-based taxonomic classification of the enzyme-producing isolates revealed that the thirteen isolates were grouped into three different classes of bacteria consisting of eight different genera. Staphylococcus, representing ∼46% of the isolates, was the most dominant genus. Measurement of enzyme-production via agar diffusion technique revealed that one of the isolates which belonged to the genus Exiguobacterium, secreted the highest amount of lipolytic and pectinolytic enzymes, whereas a Staphylococcus species produced highest proteolytic activity. The Exiguobacterium sp. expressing a maximum of four hydrolases, appeared to be the most promising isolate of all.

Probiotics and Postbiotics from Food to Health: Antimicrobial Experimental Confirmation

“…The indicator microorganism is then examined for the ability to produce exo-enzymes on agar plate assays. The agar plate contains a suitable substrate specific to each enzyme activity [56].…”

Production optimization, stability and oil emulsifying potential of biosurfactants from selected bacteria isolated from oil-contaminated sites

“…Taxonomic affiliation of the isolates was determined based on the identity of their 16S rRNA gene sequences with those in the GenBank database and with the nearest type strains in EZBioCloud database as described in [29].…”

“…PCR was carried out with the genomic DNA using the primers 27F (5 0 -AGAGTTTGATCNTGGCTCAG-3 0 ) and 1492R (5 0 -GCTTACCTTGTTACGACTT-3 0 ). Sequencing of the purified PCR products was performed as previously described [29]. The sequences were submitted to GenBank under the accession nos.…”

Detecting and Analyzing Hydrolytic Enzymes of Industrial Significance in two Streptomyces Strains Isolated from the Soil

“…Cellulase, amylase, lipase and casease activity was measured via hydrolytic capacity which is defined as the ratio of clearance zone diameter to colony diameter [11], [17], [21]. The larger ratio was treated as equivalent to higher enzyme activity.…”

“…[1]. Screening samples from the soil or marine environment for Streptomyces and other actinomycetes while assaying for bioactivity may lead to the identification of novel enzymes of industrial significance [7], [19], [17].…”