Fungal Production of Single Cell Oil Using Defatted Oilseed …
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3.8 Analysis of Fatty Acids
Lipids extracted from the biomass were analyzed by gas chromatography (GC–FID).
The retention time of the fatty acids identified showed perfect similarity with previous
GC–MS data of this study. Fatty acid contents and their ratios are shown in Table 7.
Linolenic acid was produced in a variety of range but maximum 13% was observed
in 3% flaxseed meal media in A. niger. Highest linoleic content (48.57%) was found
in added flaxseed meal medium, whereas rice bran meal supplementation enhanced
the stearic acid percentage (19.88%) in the oils produced by the fungus. The oils
produced by the fungi were more or less similar to rice bran oil in their fatty acid
composition.
Ratio of total polyunsaturated fatty acids (PUFA; 18:2 + 18:3), monounsaturated
fatty acids (MUFA; 18:1), and saturated fatty acids (SFA; 16:0 + 18:0) was calculated
and observed that it is similar to the balanced diet ratio as suggested by all dietetic
associations, which is 1:1:1.
Yao et al. (2019) showed the relationship between lipid productivity and different
organic carbon and nitrogen sources. They showed that soybean meal was the
best nitrogen source for Mortierella alpine TSM-3, producing 16.60 g/L biomass
containing 23.68% total fatty acids when glucose was used as the only carbon source.
High protein content of flaxseed, mustard, and rice bran meal supplements the media
with rich nutrients. The effect is reflected in the fatty acid composition of the oil.
High linoleic content of flaxseed may have an influence on the fungus to produce
higher linoleic acid in the oils.
4 Conclusion
In this study, Aspergillus sp produced oils in various lipid-producing media. The fatty
acid content of all oils in all media remained same, which is a remarkable finding for
assuring that these fatty acids are biomarkers for these three Aspergillus strains. The
oil produced by the fungi contained high amounts of oleic and linoleic acids. High
oleic content gives a beneficial effect. Better production of oil with better fatty acid
composition was shown in meal-supplemented media. Hence, it can be concluded
that defatted seed meals helped the isolates to improve both the quality and quantity
of oil production. The oils have an ideal PUFA, MUFA, and SFA ratio of 1:1:1.
These oils have nutritional significance and resemblance with vegetable oils. So, if
refining and toxicity checking are done, then the oils can be used as better substitute
for cooking oil.
61
3.8 Analysis of Fatty Acids
Lipids extracted from the biomass were analyzed by gas chromatography (GC–FID).
The retention time of the fatty acids identified showed perfect similarity with previous
GC–MS data of this study. Fatty acid contents and their ratios are shown in Table 7.
Linolenic acid was produced in a variety of range but maximum 13% was observed
in 3% flaxseed meal media in A. niger. Highest linoleic content (48.57%) was found
in added flaxseed meal medium, whereas rice bran meal supplementation enhanced
the stearic acid percentage (19.88%) in the oils produced by the fungus. The oils
produced by the fungi were more or less similar to rice bran oil in their fatty acid
composition.
Ratio of total polyunsaturated fatty acids (PUFA; 18:2 + 18:3), monounsaturated
fatty acids (MUFA; 18:1), and saturated fatty acids (SFA; 16:0 + 18:0) was calculated
and observed that it is similar to the balanced diet ratio as suggested by all dietetic
associations, which is 1:1:1.
Yao et al. (2019) showed the relationship between lipid productivity and different
organic carbon and nitrogen sources. They showed that soybean meal was the
best nitrogen source for Mortierella alpine TSM-3, producing 16.60 g/L biomass
containing 23.68% total fatty acids when glucose was used as the only carbon source.
High protein content of flaxseed, mustard, and rice bran meal supplements the media
with rich nutrients. The effect is reflected in the fatty acid composition of the oil.
High linoleic content of flaxseed may have an influence on the fungus to produce
higher linoleic acid in the oils.
4 Conclusion
In this study, Aspergillus sp produced oils in various lipid-producing media. The fatty
acid content of all oils in all media remained same, which is a remarkable finding for
assuring that these fatty acids are biomarkers for these three Aspergillus strains. The
oil produced by the fungi contained high amounts of oleic and linoleic acids. High
oleic content gives a beneficial effect. Better production of oil with better fatty acid
composition was shown in meal-supplemented media. Hence, it can be concluded
that defatted seed meals helped the isolates to improve both the quality and quantity
of oil production. The oils have an ideal PUFA, MUFA, and SFA ratio of 1:1:1.
These oils have nutritional significance and resemblance with vegetable oils. So, if
refining and toxicity checking are done, then the oils can be used as better substitute
for cooking oil.