Optimization of Physiological Growth Conditions for Maximal Gamma‐linolenic Acid Production by Cunninghamella blakesleeana‐JSK2

Abstract

Effects of various cultural conditions on biomass, lipid and Gamma-linolenic acid (GLA) production were investigated in the oleaginous fungus Cunninghamella blakesleeana-JSK2 isolated from soil. The GLA production was influenced by various factors such as growth condition (static and shaken), incubation time, pH, temperature, carbon and nitrogen sources. The results indicated that optimum GLA production (21 %) was obtained when the fungus was grown under shaken condition at 120 rpm for 6 days with optimum pH and temperature of 6 and 28°C ,respectively. Glucose and potassium nitrate enhanced the GLA production. Urea and sucrose were poor substances for biomass, lipid and GLA production.

Effect of Media Components and Growth Conditions for Improved Linoleic Acid Production by Beauveria Species

“…Nitrogen is beneficial for lipid production and plays an important role in regulating lipid biosynthesis (Certik et al, ). Deficiency of nitrogen ceases cell multiplication, and the cell converts carbon into lipids (Sukrutha et al, ; Wynn et al, ). However, if more nitrogen is available, more proteins and nucleic acids will be synthesized, and less nitrogen will be available for fatty acid production (Certik et al, ; Wynn et al, ).…”

“…When potassium nitrate and sodium nitrate were used as the nitrogen sources, the values were almost similar. In case of Cunninghamella spp., the highest GLA production was reported when potassium nitrate was used as the nitrogen source (Sukrutha et al, ).…”

“…The inherent pH of the GYE medium containing 10 g L −1 glucose and 3 g L −1 yeast extract was 6.8. The pH of the GYE medium was adjusted by using either 0.1 M NaOH or 0.1 N HCl, as appropriate, followed by autoclaving the medium (Sukrutha et al, ).…”

“…are becoming major concerns in their production. As an overall effect, the production of oilseeds has remained nearly stagnant over the past few years and is unable to meet the increasing demand, because of which the prices of plant oils have been increasing over the past few years (Ahmed et al, ; Sukrutha et al, ; Zhu, ).…”

“…Few oleaginous microbes can naturally accumulate lipids at more than 20% of their dry biomass (Kumar and Banerjee, ; Ratledge and Wynn, ). However, by optimizing the media components and growth conditions, it may be possible to maximize the oil production in microbes (Nisha and Venkateswaran, ; Sukrutha et al, ). Microbial oil production offers several advantages over the vegetable oil production: (1) Microbes can produce lipids with less space and shorter time; (2) can be more easily scaled up to meet the increasing demand; (3) can occur throughout the year and often using agricultural wastes as carbon sources; (4) the media used to grow them can be recycled and reused, at least partially; (5) extraction and purification of microbial oils is easier; (6) some microbes can natively produce the nutritionally important long‐chain polyunsaturated fatty acids, such as eicosapentaenoic acid (EPA) and docosahexaenoic acid (DHA), which cannot be produced by any plant, except through genetic engineering; and (7) in contrast to crop plants, genetic engineering of microbes is much easier for producing novel fatty acids or increasing the production of a given fatty acid or oil by several fold (Čertík et al, ; Ji et al, ).…”