Department of Chemistry-University of Modena and Reggio Emilia, via Campi 183, 41100 Modena, Italy.
Microb Cell Fact. 2010 Sep 23;9:73. doi: 10.1186/1475-2859-9-73.
The production of microbial lipids has attracted considerable interest during the past decade since they can be successfully used to produce biodiesel by catalyzed transesterification with short chain alcohols. Certain yeast species, including several psychrophilic isolates, are oleaginous and accumulate lipids from 20 to 70% of biomass under appropriate cultivation conditions. Among them, Rhodotorula glacialis is a psychrophilic basidiomycetous species capable to accumulate intracellular lipids.
Rhodotorula glacialis DBVPG 4785 is an oleaginous psychrophilic yeast isolated from a glacial environment. Despite its origin, the strain abundantly grew and accumulated lipids between -3 to 20°C. The temperature did not influence the yield coefficients of both biomass and lipids production, but had positive effect on the growth rate and thus on volumetric productivity of lipid. In glucose-based media, cellular multiplication occurred first, while the lipogenic phase followed whenever the culture was limited by a nutrient other than glucose. The extent of the carbon excess had positive effects on triacylglycerols production, that was maximum with 120 g L-1 glucose, in terms of lipid concentration (19 g L-1), lipid/biomass (68%) and lipid/glucose yields (16%). Both glucose concentration and growth temperature influenced the composition of fatty acids, whose unsaturation degree decreased when the temperature or glucose excess increased.
This study is the first proposed biotechnological application for Rhodotorula glacialis species, whose oleaginous biomass accumulates high amounts of lipids within a wide range of temperatures through appropriate cultivation C:N ratio. Although R. glacialis DBVPG 4785 is a cold adapted yeast, lipid production occurs over a broad range of temperatures and it can be considered an interesting microorganism for the production of single cell oils.
在过去的十年中，微生物油脂的生产引起了相当大的兴趣，因为它们可以通过与短链醇的催化酯交换成功地用于生产生物柴油。某些酵母物种，包括几种嗜冷菌，是油脂丰富的，可以在适当的培养条件下从 20%到 70%的生物质中积累油脂。其中，Rhodotorula glacialis 是一种嗜冷担子菌，能够积累细胞内油脂。
Rhodotorula glacialis DBVPG 4785 是一种从冰川环境中分离出来的油脂丰富的嗜冷酵母。尽管它的起源于寒冷的环境，但是该菌株在-3 到 20°C 之间大量生长和积累油脂。温度不影响生物质和油脂生产的产率系数，但对生长速率有积极影响，从而对油脂的容积生产率有积极影响。在基于葡萄糖的培养基中，细胞倍增首先发生，而当培养物受到除葡萄糖以外的营养物质限制时，脂生成阶段随后发生。碳过剩的程度对三酰基甘油的生产有积极影响，在 120 g/L 葡萄糖的情况下，以油脂浓度（19 g/L）、油脂/生物质（68%）和油脂/葡萄糖产率（16%）计，达到最大值。葡萄糖浓度和生长温度都影响脂肪酸的组成，随着温度或葡萄糖过剩的增加，脂肪酸的不饱和程度降低。
本研究首次提出了 Rhodotorula glacialis 种的生物技术应用，其油脂丰富的生物质在适当的 C:N 培养比下，在较宽的温度范围内积累大量油脂。尽管 R. glacialis DBVPG 4785 是一种适应寒冷的酵母，但在较宽的温度范围内都能进行油脂生产，它可以被认为是生产单细胞油的一种有趣的微生物。
