Protease Producing Bacteria and Activity in Gut of Tiger Shrimp (Penaeus monodon)

Abstract

Proteases, the group of enzyme with significant commercial value, was isolated from proteolytic bacteria available in gut of tiger shrimp (Penaeus monodon). The isolation of bacteria from the gut of the collected shrimp was performed by serial dilution and plating method. Six bacterial isolates were screened out on the basis of their formation of zone of casein hydrolysis on skim milk agar. Among the six isolates, three isolates (S 1 , S 3 and S 5 ) were found gram positive and the rest three isolates (S 2 , S 4 and S 6 ) were found gram negative. Protease activity of the isolates was determined both qualitatively and quantitatively. In qualitative plate assay, isolate S 1 exhibited the largest clear zone (30±1.13 mm) in skim milk agar and isolate S 5 exhibited the lowest (18±1.41 mm). Quantitative protease assay was performed by using azo-casein as substrate. Protease activity of isolates S 1 , S 2 , S 3 , S 4 , S 5 and S 6 were found 49.75±2.13, 60.50±1.97, 66.25±2.41, 56.25±1.69, 59.25±1.32 and 52.75±2.21 U mLG 1 , respectively following incubation at 37°C in aerobic condition for 24 h. The effect of pH and NaCl concentration on the growth and protease production of the isolates were also studied by assaying protease activity at different pH range and NaCl concentrations. The isolates exhibited maximum protease production at varying pH and NaCl concentrations. The data showed potentiality of the bacterial isolates to be a useful source of industrial protease. Finally, the isolates were also tested against six standard antibiotics (Tetracycline, Nitrofurantoin, Erythromycin, Penicillin, Ciprofloxacin and Doxycycline) to observe their antibiotic sensitivity and the isolates S 5 and S 6 were found resistant to all of the six antibiotics and isolates S 3 and S 4 were found sensitive to all of the antibiotics.

Antifouling Potential of Ethyl Acetate Extract of Marine Bacteria Pseudomonas aeruginosa Strain RLimb

“…Furthermore, the isolate exhibited catalase and oxidase activity by producing air bubbles and turning blue. In the catalase test, the isolate produced free oxygen in the form of air bubbles as soon as hydrogen peroxide was added [ 38 ]. Whether it was oxidase positive was determined by the oxidation of the Kovacs reagent, which turned blue [ 72 ].…”

“…The isolated bacteria incubated overnight on marine agar were screened for the production of lipase, amylase, and protease enzymes using different types of agar composition. The lipase production of the bacterial isolate was quantified based on a spirit blue agar plate [ 37 ]; protease activity was tested using 1.0% ( w/v ) skimmed milk agar [ 38 ]; and amylase production was tested using 0.4% ( w/v ) starch agar [ 39 ], with some modifications. The agar (BD Difco TM , Thermofisher Scientific, USA) was prepared and sterilized at 121 °C for 20 min.…”

Characterization of Lactic Acid Bacteria from the Gut of Penaeus vannamei as Potential Probiotic

“…The gut bacterial isolates were evaluated for digestive enzyme activity viz., the protease (Bhowmik et al, 2015), amylase, lipase and cellulase (Das et al, 2014) using plate screening method. Antibacterial activity of the isolates was studied against the Vibrio campbelli, V. harveyi and V. parahaemolyticus obtained from Aquatic Animal Health and Environment Division, ICAR-CIBA, Chennai, by agar well diffusion assay (W an na et al ., 20 21 ;Kaewchomp hunuc h et al, 2022;Raj yalakshmiet al,2021).The plates were examined for clearing zones around the wells after 24 hours of incubation at 30C, with sterile MRS broth as negative control and tetracycline disc (TE: SD037-Hi media) as positive control.…”

Diversity, activity, and effectiveness of Rhizobium bacteria as plant growth promoting rhizobacteria (PGPR) isolated from Dieng, central Java

“…Protease production activity was tested qualitatively using a skim milk agar (SMA) as in Bhowmik et al ( 17 ). The bacteria were inoculated and incubated at 28–30°C for 2–5 days.…”