RESUMO
BACKGROUND: Lipase enzymes have applications in a wide range of industries. A crucial determining factor of industrial prices of these enzymes is the culture media composition that is constantly under review by researchers. In this work, for maximum lipase production by Bacillus sp. ZR-5, culture media compositions were optimized using â³one variable at a timeâ³ strategy. METHODS: For this purpose, the culture medium parameters such as low and high cost carbon and nitrogen sources, substrates and incubation times were evaluated. RESULTS: Maximum lipase activity was achieved after 24 hr of incubation with 1.5% of glucose syrup (1600±69.1 u/mg), 1% of fish powder (1238±36.7 u/mg) and olive oil (1407±2.1 u/mg) as low cost carbon and nitrogen sources and substrate, respectively. CONCLUSION: Our results show a significant increase in lipase activity with usage of low cost sources; this could help in reducing the media prices for industrial application of lipase enzyme.
RESUMO
The purpose of the present study was to screen and identify the lipase-producing microorganisms from various regions of Iran. Samples collected from hot spring, Persian Gulf, desert area and oil-contaminated soil, were analyzed for thermophilic extracellular-lipase producing organisms. Six strains with high activity on rhodamine B plates were selected for chemical identification and further study. Among these isolated bacteria, four strains show higher activity in pH-Stat method at 55 °C. These strains were identified by PCR amplification of 16s rRNA genes using universal primers. Fermentation increased the activity up to 50%. The growth medium, designed for lipase production, increased the activity up to 4.55 folds. The crude supernatant of ZR-5 after fermentation and separation the cells, was lyophilized and the activity was measured. Total activity of this strain was 12 kU/g that shows its potential for industrial uses. Further study is required for purification of enzyme and calculation its specific activity. Immobilization is another approach should be considered.
Assuntos
Bactérias/enzimologia , Bactérias/isolamento & purificação , Lipase , Técnicas de Tipagem Bacteriana , Bactérias/classificação , Bactérias/genética , Meios de Cultura/química , DNA Ribossômico/química , DNA Ribossômico/genética , Microbiologia Ambiental , Estabilidade Enzimática , Concentração de Íons de Hidrogênio , Irã (Geográfico) , Lipase/química , Dados de Sequência Molecular , /genética , Análise de Sequência de DNA , TemperaturaRESUMO
The purpose of the present study was to screen and identify the lipase-producing microorganisms from various regions of Iran. Samples collected from hot spring, Persian Gulf, desert area and oil-contaminated soil, were analyzed for thermophilic extracellular-lipase producing organisms. Six strains with high activity on rhodamine B plates were selected for chemical identification and further study. Among these isolated bacteria, four strains show higher activity in pH-Stat method at 55 °C. These strains were identified by PCR amplification of 16s rRNA genes using universal primers. Fermentation increased the activity up to 50%. The growth medium, designed for lipase production, increased the activity up to 4.55 folds. The crude supernatant of ZR-5 after fermentation and separation the cells, was lyophilized and the activity was measured. Total activity of this strain was 12 kU/g that shows its potential for industrial uses. Further study is required for purification of enzyme and calculation its specific activity. Immobilization is another approach should be considered.
