Growth of a tropical marine yeast Yarrowia lipolytica NCIM 3589 on bromoalkanes: relevance of cell size and cell surface properties

Abstract

Yarrowia lipolytica 3589, a tropical marine yeast, grew aerobically on a broad range of bromoalkanes varying in carbon chain length and differing in degree and position of bromide group. Amongst the bromoalkanes studied, viz. 2-bromopropane (2-BP), 1-bromobutane (1-BB), 1,5-dibromopentane (1,5-DBP) and 1-bromodecane (1-BD), the best utilized was 1-BD, with a maximal growth rate (m max ) of 0.055 h À1and an affinity ratio (m max /K s ) of 0.022. Utilization of these bromoalkanes as growth substrates was associated with a concomitant release of bromide (8202.9 mM) and cell mass (36 Â 10 9 cells/ml), occurring maximally on 1-BD. Adherence of yeast cells to these hydrophobic bromoalkanes was observed microscopically, with an increase in cell size and surface hydrophobicity. The maximal cell diameter was for 1-BD (4.66 mm), resulting in an increase in the calculated cell surface area (68.19 mm 2 ) and sedimentation velocity (1.31 mm/s). Cell surface hydrophobicity values by microbial adhesion to solvents (MATS) analysis for yeasts grown on bromoalkanes and glucose were significantly high, i.e. >80%. Similarly, water contact angles also indicate that the cell surface of yeast cells grown in glucose possess a relatively more hydrophilic cell surface (θ = 49.1 ), whereas cells grown in 1-BD possess a more hydrophobic cell surface (θ = 90.7). No significant change in emulsification activity or surface tension was detected in the cell-free supernatant. Thus adherence to the bromoalkane droplets by an increase in cell size and surface hydrophobicity leading to debromination of the substrate might be the strategy employed in bromoalkane utilization and growth by Y. lipolytica 3589.

Biotechnological applications of Yarrowia lipolytica: Past, present and future

“…Bromoalkanes, as hydrophobic organic compounds, can usually be degraded by bacteria under aerobic and anaerobic conditions. However, Vatsal et al (2011) presented that Y. lipolytica NCIM 3589 is also able to utilize a broad range of bromoalkanes with different carbon chain lengths that vary in degree and position of bromide substitution for the first time and 1-bromodecane was the best utilized substrate among the bromoalkanes tested.…”

Yarrowia lipolytica: Safety assessment of an oleaginous yeast with a great industrial potential

“…Moreover, various applications of Y. lipolytica in bioremediation and detoxification have been proposed, for example (i) bioremediation of hydrocarbon-contaminated soils or aquatic environments, (ii) detoxification of 2,4,6-trinitrotoluene (TNT), methyl parathion, aflatoxins or brominated organics, (iii) treatment and upgrading of waste streams (e.g. olive mill wastewater, palm oil mill effluents), or (iv) metal detoxification (Bankar et al, 2009;Mann & Rehm, 1977;Shinde et al, 2012;Song et al, 2011;Vatsal et al, 2011;Wang et al, 2012). The Belgian company Artechno (http://www.artechno.be) has a small business using a non-GMO Yarrowia lipase product for the treatment of lipid-rich wastewater (Bordes et al, 2011).…”

Phenol Is the Initial Product Formed during Growth and Degradation of Bromobenzene by Tropical Marine Yeast, Yarrowia lipolytica NCIM 3589 via an Early Dehalogenation Step

“…For growth kinetics, Y. lipolytica NCIM 3589 cells (2 × 10 9 ) were inoculated in 250 mL bottles containing MMY medium (50 mL) along with varying BrB concentrations (0.1–2.0%, v/v; 9.5–190 mM) and were sealed with Teflon-lined screw caps. These cells were allowed to grow aerobically at 30°C with a shaking speed of 150 rpm for a time period of 72 h. After growth, cells were centrifuged; pellet was washed with autoclaved distilled water, vortexed for separating the cells and absorbance measured at A 600 , wherein 1 OD was equivalent to 2 × 10 9 cells/mL (Vatsal et al, 2011). The growth kinetic parameters were determined based on the relationship between the initial concentration of BrB and the specific growth rate and calculated by non-linear regression using Microcal Origin 6.0.…”

“…The past few years have seen the emergence of non-conventional yeasts such as Yarrowia lipolytica , which play an important role in the bioremediation of numerous industrial and environmental waste compounds (Bankar et al, 2009). A well-known property of Y. lipolytica is the ability to adhere and degrade hydrophobic substrates such as oils, n -alkanes and bromoalkanes (Fickers et al, 2005; Vatsal et al, 2011, 2015). We report here studies on Y. lipolytica NCIM 3589, which has been isolated from the marine water samples collected from areas near the offshore oil rig Mumbai High, contaminated with crude oil and industrial effluents.…”

“…As Y. lipolytica 3589 was isolated from an oil polluted zone and able to tolerate the harsh environmental conditions, it was anticipated to have the potential for utilizing brominated compounds for growth. In our earlier studies, we have reported the ability of this yeast to utilize and grow on brominated aliphatic compounds having different carbon chain lengths and different position and degree of the substituent bromide group (Vatsal et al, 2011, 2015). The growth kinetics would differ on the bromoaromatics present in the environment, depending on their bioavailability and the inherent capacity of the yeast to degrade them.…”