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

Bioaugmentation of biofloc system with enzymatic bacterial strains for high health and production performance of Penaeus indicus

Not AvailableThe beneficial effects of two probiotic bacterial strains Marinilactibacillus piezotolerans and Novosphingobium sp. during the culture of Indian white shrimp, Penaeus indicus, under biofloc and clear water system were evaluated. The experimental variation were CW1 (M. piezotolerans in clear water), BFT1 (biofloc + M. piezotolerans), CW2 (Novosphingobium sp. in clear water), BFT2 (biofloc + Novosphingobium sp.) and control (without bacterial strains and biofloc). Growth and survival considerably increased in probiotic bio-augmented treatments. Probiotic incorporation significantly improved water quality, especially ammonia reduction. Microbiota analysis from gut samples taken from different treatments revealed varied microbial population structure among clear water culture, biofloc culture and control. Proteobacteria and Firmicutes were the top phyla observed in the treatments which were significantly higher in bio-augmented systems than the control. Vibrio genera were predominantly observed in control and clear water system compared to that of biofloc systems. Immune genes were significantly altered in response to probiotic gut microbial supplementation than the control. Higher gene expression profile of important immune genes was observed in the biofloc reared shrimps. Expression of digestive enzyme related genes such as trypsin, chymotrypsin, cathepsin L, cathepsin B and alpha amylase were also upregulated significantly in probiotic supplementation especially in the biofloc treatments. Proteomic analysis of hepatopancreas of shrimps from different treatments was carried out by using 2D gel electrophoresis and MALDITOF analysis. The proteins were mostly related to growth and stress tolerance. Eukaryotic initiation factor 4E binding protein was expressed in all the groups and it was high in biofloc treated animals followed by animals treated solely with probiotics compared to those of control groups. The results concludes that biofloc already proved as an effective culture method for healthy shrimp production and supplementation of probiotic bacterial strains registered additional benefit for growth, survival, microbial, immunological status of P, indicus culture.Not Availabl

Enzyme production from food wastes using a biorefinery concept

According to Food and Agricultural Organization (FAO), one-third of food produced globally for human consumption (nearly 1.3 billion tonnes) is lost along the food supply chain. In many countries food waste is currently landfilled or incinerated together with other combustible municipal wastes for possible recovery of energy. However, these two options are facing more and more economic and environmental stresses. Due to its organic- and nutrient-rich nature, theoretically food waste can be converted to valuable products (e.g. bio-products such as methane, hydrogen, ethanol, enzymes, organic acids, chemicals and fuels) through various fermentation processes. Such conversion of food waste is potentially more profitable than its conversion to animal feed or transportation fuel. Food waste valorisation has therefore gained interest, with value added bio-products such as methane, hydrogen, ethanol, enzymes, organic acids, chemicals, and fuels. Therefore, the aim of this review is to provide information on the food waste situation with emphasis on Asia–Pacific countries and the state of the art food waste processing technologies to produce enzymes

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

Evaluation of Mechanical Behaviour of Multiwalled Nanotubes Reinforcement Particles in Jute-Glass Fibres Hybrid Composites

Fibre-reinforced polymers (FRPs) are composite materials of plastics reinforced with fibres. Cars, sea, aeronautics, and foundation projects progressively utilize fibre-reinforced polymers. This study aims to study the effect of adding multiwalled nanotubes fillers into the hybridized jute-glass FRP composites and their relative properties. This study uses multiwalled nanotubes (MWCNTs), and particles-hybrid jute-glass composites containing jute fibre chopped layer mats, woven glass mats, epoxy resin, and multiwalled nanotubes fillers were created using the hand layup method. After adding multiwalled nanotubes fillers in various weight proportions, the mechanical behaviours of fibre-reinforced polymers were analysed. The mechanical behaviours of laminated composites were tested using the ASTM standard; the following properties are tensile, flexural, and impact strength. The multiwalled nanotubes with 6% wt. attained the maximum mechanical properties compared to the 2 and 4 wt. % of MWCNTs. The E-based specimen contributes the most to the different types of specimens, with a contribution of 24.21% for tensile, 25.03% for flexural, and 24.56% for impact. The microstructures of hybrid composites were studied using a scanning electron microscope

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

Tensile, Dynamic Mechanical, and Vibration Behavior of Layering Sequence Design Effect of Glass Intertwined Natural Kenaf Woven Polymeric Laminates

ABSTRACTThis study focuses on developing a fiber stacking of polymer laminate for high-impact load-absorbing applications, such as aircraft, automotive, and soundproofing structures. Therefore, the effect of high-strength fiber position effect on the tensile and dynamic behaviors of woven glass intertwined kenaf fiber thermoset composites was investigated in this research work. The tensile strength and dynamic mechanical properties of a hybrid stacking composite designed with maximum glass fiber, especially glass as an outer layer, are relatively higher. The outer layer of glass fiber is particularly effective in containing stress due to its high-strength characteristics, reducing stress transmission to the other core layers. The maximum storage of outer glass and inner kenaf woven stacking composite S1 were 7692.4 MPa, respectively. Besides, the most significant improvement in damping value was observed for the outer glass stacking kenaf (S1) composite compared to the all-other woven glass stacked composite. Furthermore, the composite with the outer glass layers and inner kenaf layers shows a more significant damping value due to the porous structure of the kenaf fibers, allowing for more excellent vibration energy dissipation. Overall, the stacking composites with a glass and kenaf layering arrangement exhibit good mechanical properties for high-impact load-absorbing applications

Not Available

Not AvailableThe beneficial effects of two probiotic bacterial strains Marinilactibacillus piezotolerans and Novosphingobium sp. during the culture of Indian white shrimp, Penaeus indicus, under biofloc and clear water system were evaluated. The experimental variation were CW1 (M. piezotolerans in clear water), BFT1 (biofloc + M. piezotolerans), CW2 (Novosphingobium sp. in clear water), BFT2 (biofloc + Novosphingobium sp.) and control (without bacterial strains and biofloc). Growth and survival considerably increased in probiotic bio-augmented treatments. Probiotic incorporation significantly improved water quality, especially ammonia reduction. Microbiota analysis from gut samples taken from different treatments revealed varied microbial population structure among clear water culture, biofloc culture and control. Proteobacteria and Firmicutes were the top phyla observed in the treatments which were significantly higher in bio-augmented systems than the control. Vibrio genera were predominantly observed in control and clear water system compared to that of biofloc systems. Immune genes were significantly altered in response to probiotic gut microbial supplementation than the control. Higher gene expression profile of important immune genes was observed in the biofloc reared shrimps. Expression of digestive enzyme related genes such as trypsin, chymotrypsin, cathepsin L, cathepsin B and alpha amylase were also upregulated significantly in probiotic supplementation especially in the biofloc treatments. Proteomic analysis of hepatopancreas of shrimps from different treatments was carried out by using 2D gel electrophoresis and MALDI-TOF analysis. The proteins were mostly related to growth and stress tolerance. Eukaryotic initiation factor 4E binding protein was expressed in all the groups and it was high in biofloc treated animals followed by animals treated solely with probiotics compared to those of control groups. The results concludes that biofloc already proved as an effective culture method for healthy shrimp production and supplementation of probiotic bacterial strains registered additional benefit for growth, survival, microbial, immunological status of P, indicus culture.Not Availabl

Not Available

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