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1.
PLoS One ; 17(8): e0273368, 2022.
Artigo em Inglês | MEDLINE | ID: mdl-36040973

RESUMO

Five Bacillus cereus strains including B. cereus AVP12, B. cereus NC7401, B. cereus BDBCO1, B. cereus JF70 and B. specie JL47 isolated from the diesel fuel polluted soil adhered to the roots of Tagetes minuta were screened for lipase production with phenol red agar method. B. cereus NC7401 strain successfully expressing and secreting lipase with maximal lipolytic activity was subjected to a submerged fermentation process with five different carbon (starch, glucose, maltose, fructose, and lactose) and five different nitrogen (tryptone, ammonium nitrate, peptone, urea, yeast extract) sources to produce lipase enzyme. Maximum enzyme activity was found with starch (30.6 UmL-1), maltose (40 UmL-1), and tryptone (38.6 UmL-1), and the lipases produced using these sources were named lipase A, B, and C respectively. The total protein content of 8.56, 8.86, and 2.75 µg mL-1 were obtained from B. cereus NC7401 cultured using starch, maltose, and tryptone respectively. Lipase was stable between temperature range 30-80°C and pH 5-10 whereas optimally active at 55°C and pH 8.0. The enzyme was relatively stable for 10 days at 4°C and its optimum reaction time with the substrate was 30 minutes. It was tolerant to 1.5% (v/v) methanol as an organic solvent, 1.5% (v/v) Triton X-100 as a media additive and 1.5% (w/v) Ni2+ as a metal ion. SDS, n-hexane, and Ag+ inhibited lipolytic activity. Oil stains were removed from cotton fabric which showed oil removal efficiency enhancement in the presence of a lipase. Fat hydrolysis of 20, 24, and 30% was achieved following 6 hours of incubation of the fat particles with lipase A, B, and C respectively at a concentration of 20 mg mL-1. To as best of our knowledge, this study on lipases extracted from bacteria of Azad Kashmir, Pakistan origin has never been reported before.


Assuntos
Bacillus cereus , Lipase , Bacillus cereus/metabolismo , Gasolina , Concentração de Íons de Hidrogênio , Lipase/metabolismo , Maltose , Solo , Amido , Temperatura
2.
PLoS One ; 17(6): e0269444, 2022.
Artigo em Inglês | MEDLINE | ID: mdl-35658061

RESUMO

The antioxidant capacity of extracts of different parts of Cucurbitaceae vegetables was evaluated by DPPH (2, 2-diphenyl-1-picrylhydrazyl) and ABTS (2, 2'-azino bis (ethyl benzothiazoline 6)-sulphonic acid) methods. Total phenolic content (TPC) and total flavonoid content (TFC) were also determined. The correlation of TPC, TFC, DPPH, and ABTS in different extracts of Cucurbitaceae vegetables was analyzed. The peel extracts of studied vegetables had the highest TPC, (C. grandis 3.00±0.86, T. cucumerina 3.24±0.70 and C. moschata 3.12±0.06 mg gallic acid equivalent (GAE) g-1 DW) and TFC (C. grandis 18.96±1.5, T. cucumerina 13.92±1.41 and C. moschata 15.31±0.97 mg rutin equivalent (RE) g-1 DW). The maximum antioxidant potential was obtained by the ABTS method in peel extracts of C. grandis (78.7%) and C. moschata (63.5%) while in pulp extract of T. cucumerina (50.1%) at 10 µg/mL. The percent radical scavenging activity (% RSA) by the DPPH method found maximum for peel and pulp of C. grandis (45.15 and 45.15%, respectively) and peel of T. cucumerina (45.15%) and C. moschata (34.15%). The EC50 obtained in the ABTS method was 0.54 and 7.15 µg/mL for C. grandis and C. moschata, respectively while 0.81 µg/mL for the pulp of T. cucumerina compared to standard ascorbic acid (1.05 µg/mL). The EC50 calculated in the DPPH method was 11.78 µg/mL, 13.34 µg/mL, and 21.00 µg/mL for C. grandis, T. cucumerina, and C. moschata peel respectively compared to the standard Butylated hydroxytoluene (BHT). Among each variable, the correlation between ABTS and TPC provided the highest positive correlation (r = 0.998, p< 0.05) in peel extracts.


Assuntos
Cucurbitaceae , Verduras , Antioxidantes/química , Flavonoides/farmacologia , Fenóis/química , Extratos Vegetais/química , Extratos Vegetais/farmacologia , Verduras/química
3.
Biotechnol Prog ; 37(1): e3092, 2021 01.
Artigo em Inglês | MEDLINE | ID: mdl-33058555

RESUMO

Lipase was extracted from germinating seeds of Helianthus annus (Sunflower), Zea mays (Maize), and Brassica compastris (Mustard). The lipolytic activity was assessed using olive oil as substrate at different germination-time and the maximum-activity was obtained after 120 hr. Partial-purification was executed by precipitating the seed-homogenate with varying concentration of ammonium sulfate solution. 80% ammonium sulfate solution showed maximum lipase activity of 5320IUml-1 , 3500IUml-1 , 3080IUml-1 with 9.6, 6.9, and 4.8-fold purification and total protein content of 162, 84, and 60 mg for partially purified enzyme extracts namely SN5, BN5, and MN5, respectively. The optimum temperature and pH observed for hydrolysis of olive oil were 37°C, and 8.0 respectively. Enzyme was found to be stable upto 6 days at 4°C and its activity was stimulated by Ca+2 ions. Oil-stains removal from cotton fabric was observed to be superior in the presence of lipase and detergent. Moreover, the SN5, BN5, and MN5 lipase increased free fatty acid release upto 4.2, 4.3, and 3.8 mg, respectively than wastewater without treatment of lipase (0.21 mg) and promoted fat hydrolysis to approximately 40, 42, and 48% mass reduction after 6 hr incubation of fat particle at a concentration of 20 mg/ml. Biodiesel produced by catalyzing transesterification of vegetable oil with SN5, BN5, and MN5 lipase provided an acid value of 0.8, 1.08, and 0.5 mg/g, viscosity 5.50, 5.7, and 5.53 mm2 /s and density 0.87, 0.88, and 0.79 g/ml, respectively. To the best of our knowledge, no such study has been conducted prior on lipase from the seeds mentioned above in Azad Kashmir region.

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