Biosurfactant production by yeasts from different types of soil of the South Shetland Islands (Maritime Antarctica)

Abstract

Aim To screen and identify a potential biosurfactant‐producing yeast strain isolated from Antarctic soil and to evaluate the fermentation process kinetics of the most promising strain on biosurfactant production using glycerol as carbon source. Methods and Results From the 68 isolated yeast strains, 11 strains were able to produce biosurfactants after Emulsification Index (E.I.) and Drop Collapse tests, reaching an E.I. higher than 10%. Strain 1_4.0 was the best producer, identified as Candida glaebosa based on molecular analysis. Yeast was cultivated in a medium composed of glycerol supplemented with yeast extract for 120 h to determine the process kinetics. The increased C/N ratio affected yeast growth and biosurfactant production. Biosurfactant release was associated with the end of exponential and beginning of the stationary growth phases. Results indicated an E.I. of 30% at the end of the fermentation. Conclusions The feasiability of C. glaebosa to produce biosurfactant from a low‐cost medium cultivation shows a great impact on the development of bioresource in the Antarctica terrestrial environment. Significance and Impact of the Study Although the diversity of psychrophilic/psychrotolerant micro‐organisms from Antarctica has been the preferred subject of study by microbiologists, terrestrial microfungal communities are scarcely investigated and literature about the biotechnological potential of such micro‐organisms should cover important biomolecules in addition to cold‐adapted enzymes. In the present study, for the first time, the Maritime Antarctica environment was screened as a novel source of biosurfactants produced by micro‐organisms.

Fungal biosurfactants, from nature to biotechnological product: bioprospection, production and potential applications

“…On the other hand, the search for biosurfactant-producing fungi can also be carried out through approaches that exploit extreme environments [ 155 ] and cultivation-independent techniques (metagenomics), as total environmental DNA can be examined at sequence level or be function-oriented [ 149 , 156 ]. Functional metagenomics identifies genes or pathways in an environmental clone library by their functional activity (in this case, produce biosurfactants), providing an advantage over sequence-based screening, principally due to the fact that no prior knowledge of the gene sequence for target activity is required [ 157 ].…”

“…In addition, extremophilic yeast Moesziomyces antarcticus (previously classified as Candida antarctica ) produced biosurfactants such as mannosylerythritol lipids [ 164 ] and diacylmannosylerythritol [ 165 ], the latter interfered with ice paste formation as they have an anti-agglomeration effect and a high ice packing factor [ 161 ]. Among 68 yeasts isolated from Antarctic soils, only 11 produced biosurfactants, with Candida glaebosa as the most prominent [ 155 ]. Recently, other yeasts isolated from Antarctic marine and terrestrial environments such as Meyerozyma guilliermondii L21, Cryptococcus victoriae L92 and Leucosporidium scotti L120 have been reported as biosurfactant producers [ 166 ].…”

“…This condition is advantageous for the industry since it does not increase costs related to the cooling stages of the culture medium [ 136 ]. However, the thermophilic fungi Fusarium fujikuroi produces trehalose lipids with lower surface tension (20.08 mNm −1 ) at 47 °C [ 107 ] while psychotolerant yeasts isolated from cold environments produce biosurfactants at 20 °C [ 155 ].…”

Physiological and biochemical traits of yeasts from soils of various ecosystems of East Antarctica

“…The rest of the culture broth was used for the wetting test and the drop collapse test (Fedorova et al, 2010;Bueno et al, 2019).…”

“…Gribanova, V. Miamin: Physiology & biochemistry of yeasts (E Antarctica) we used a drop of distilled water and measured its diameter. The larger the difference between the tested culture's diameter compared to the water drop's diameter, the higher the wetting activity of the suspension (Fedorova et al, 2010;Bueno et al, 2019).…”