Proizvodnja lipaze s pomoću bakterije Serratia rubidaea izolirane iz mlijeka

Production of extracellular lipase in submerged culture of Serratia rubidaea has been investigated. The lipase production was optimized in shake flask experiments. The observed pH and temperature range optimum for maximum lipase production were 7–8 and 30–40 °C, respectively. With a selected nitrogen source, casein ((6.5±0.015) U/mL) and soytone ((9.4±0.02) U/mL) were suitable substrates for accelerating lipase production. The optimized concentration of casein and soytone was 24 g/L ((9.95±0.02) U/mL) and 5 g/L ((14.8±0.03) U/mL), respectively. The effect of carbon source on lipase production indicated that starch was suitable substrate to maximize lipase production ((15.60±0.20) U/mL) and the optimum concentration registered was 4 g/L ((17.46±0.20) U/mL). Investigating the effect of lipids and surfactants showed that the gingily oil ((20.52±0.20) U/mL) and Tween 20 ((27.10±0.01) U/mL) were suitable substrates for maximizing lipase production, and the optimum concentrations registered were 15 mL/L ((23.15±0.24) U/mL) and 6 mL/L ((34.20±0.01) U/mL), respectively. Partial purification of lipase indicated that the molecular mass of partially purified enzyme was 54 kDa.U radu je istražena proizvodnja ekstracelularne lipaze pri submerznom uzgoju bakterije Serratia rubidaea, optimirana pokusima na tresilici. Za maksimalnu proizvodnju lipaze optimalna pH-vrijednost bila je 7-8, a optimalna temperatura 30-40 °C. Primjenom kazeina ((6,5±0,015) U/mL) i peptona iz soje ((9,4±0,02) U/mL) kao izvora dušika, pospješena je proizvodnja lipaze. Optimirana koncentracija kazeina iznosila je 24 g/L ((9,95±0,02) U/mL), a peptona iz soje 5 g/L ((14,8±0,03) U/mL). Za maksimalnu proizvodnju lipaze ((15,60±0,20) U/mL) najbolji izvor ugljika bio je škrob, pri optimalnoj koncentraciji od 4 g/L ((17,46±0,20) U/mL). Ispitivanje utjecaja lipida i površinski aktivnih tvari pokazalo je da su sezamovo ulje ((20,52±0,20) U/mL) i Tween 20 ((27,10±0,01) U/mL) najprikladniji supstrati za maksimalnu proizvodnju lipaze. Optimalni volumni udio sezamovog ulja bio je 15 mL/L ((23,15±0,24) U/mL), a Tweena 20 je bio 6 mL/L ((34,20±0,01) U/mL). Djelomično pročišćavanje lipaze pokazalo je da je njezina molekularna masa 54 kDa

Investigation of Lipase Production by Milk Isolate Serratia rubidaea

Production of extracellular lipase in submerged culture of Serratia rubidaea has been investigated. The lipase production was optimized in shake flask experiments. The observed pH and temperature range optimum for maximum lipase production were 7–8 and 30–40 °C, respectively. With a selected nitrogen source, casein ((6.5±0.015) U/mL) and soytone ((9.4±0.02) U/mL) were suitable substrates for accelerating lipase production. The optimized concentration of casein and soytone was 24 g/L ((9.95±0.02) U/mL) and 5 g/L ((14.8±0.03) U/mL), respectively. The effect of carbon source on lipase production indicated that starch was suitable substrate to maximize lipase production ((15.60±0.20) U/mL) and the optimum concentration registered was 4 g/L ((17.46±0.20) U/mL). Investigating the effect of lipids and surfactants showed that the gingily oil ((20.52±0.20) U/mL) and Tween 20 ((27.10±0.01) U/mL) were suitable substrates for maximizing lipase production, and the optimum concentrations registered were 15 mL/L ((23.15±0.24) U/mL) and 6 mL/L ((34.20±0.01) U/mL), respectively. Partial purification of lipase indicated that the molecular mass of partially purified enzyme was 54 kDa

Colonization of enzymatic bacterial flora in biofloc grown shrimp Penaeus vannamei and evaluation of their beneficial effect

Not AvailableExperiments were conducted to explore the colonization of beneficial bacteria in shrimp Penaeus vannamei grown in different sources of biofloc and clear water. Beneficial effect in terms of extracellular enzyme production and antibiofilm activity of the isolated strains was determined. Heterotrophic bacterial population were isolated by using different agar plates and resulted in isolation of 94 isolates in total. Extracellular enzyme production such as amylase, protease, lipase, cellulase, xylanase, and pectinase were screened. Antibiofilm activity of culture supernatants of enzymatic strains against pathogenic Vibrio was also determined. Out of 94 strains screened, 36 strains were found to produce amylase enzyme, 20 strains protease, 27 strains lipase, 6 strains cellulase, and 8 strains xylanase. Totally, 21 isolates selected for further identification and different species of Cobetia, Exiguobacterium, Bacillus, Marinilactibacillus, Staphyllococcus, and Novosphingobium genera from biofloc treatments were identified. In control group animals, strains of Bacillus and Exiguobacterium were isolated and identified. The genus Exiguobacterium was found common in all the different treatments and control. The result showed that shrimp grown on biofloc system allows colonizing more beneficial bacteria in gut than control. Few promising strains under Bacillus genus were found to produce all the extracellular enzymes along with antibiofilm activity.Not Availabl

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Not AvailableA two-month experiment was conducted to evaluate the effect of complex carbon sources on the biofloc system and its influence on Penaeus vannamei culture. Four sources of carbon viz. Tapioca flour (BFTf), Rice bran (BFRb), Wheat flour (BFWf), Rice Flour (BFRf), and biofloc were generated, the absence of CHO being considered as control (C). The experiment was carried out in 100L FRP tanks in triplicate, and the post-larvae (ABW: 0.11 g) were stocked @ 400 PL/m3 . Results revealed that the addition of complex carbon sources effectively reduces the TAN by 62-67%. The average body weight of shrimp in the rice flour and wheat flour treatments were significantly higher compared to control. Similarly, improved survival was observed in rice bran treatment (89%). Beneficial bacteria were isolated from all the treatments as well as control. Real-time analysis revealed significantly (P<0.05) higher expression of digestive enzyme-related genes compared to control the utilization of carbohydrates, exhibiting an encouraging trend. The complex carbon sources (BFRf) and (BFWf) have been effectively utilized, resulting in improved water quality, microbial diversity, growth performance, and enhanced digestive enzyme activity.Not Availabl