A series of 4‐decyloxy‐4′‐hydroxybiphenyl esters of α,ω‐alkanedicarboxylic acids containing two mesogenic units connected by a methylene spacer was synthesized. The mesogenic properties of the compounds were investigated by polarising optical microscopy, differential scanning calorimetry and X‐ray diffraction methods. A strong influence of the spacer length and its parity on the mesomorphic properties was found. A dramatic odd–even effect was observed for the clearing temperatures and entropies. Compounds with an even number of carbon atoms in the methylene spacer formed tilted smectic phases, whereas compounds with an odd number of carbon atoms in the spacer exhibited the B4 phase, characteristic of bent‐shaped molecules.

Single cell oil (SCO) is the lipid accumulated in the cells of oleaginous microorganisms. Cellular lipids can be synthesized in two different pathways: de novo by metabolizing hydrophilic substrates and ex novo by fermenting hydrophobic substrates. The aim of the study was to evaluate the effect of carbon source (glucose and olive oil) in the culture medium on the course of microbial oil accumulation in Y. lipolytica cells. The level of selected gene expression by real time quantitative PCR method was investigated. The significant increase in expression of the POX2 gene encoding acyl-CoA oxidase II, which preferentially oxidizes long-chain acyl-CoAs formed from substrate fatty acids incorporated inside the microbial cell, was observed in medium with olive oil in relation to glucose containing medium. Noteworthily, the presence of lipid carbon substrate did not inhibit the level of ACL gene transcription coding for ATP-citrate lyase, the key enzyme of the lipid de novo accumulation process. The present study indicated that de novo lipid biosynthesis could occur despite the presence of fatty acids in the medium, and the synthesis of storage lipids in the presence of lipid carbon substrates could be carried out with the use of both pathways (de novo and ex novo).

The production of lipases by microorganisms is strongly influenced by the culture conditions. The optimum culture conditions for enzyme production are strain- and species-dependent. The aim of this study was to evaluate the impact of the carbon source used in the culture medium on the profile of lipases produced by Yarrowia lipolytica KKP 379. We observed a different pattern of extracellular and cell-bound lipase production, which was the highest in the early exponential phase. The extracellular lipase activity increased in the late exponential phase due to the lower accumulation of lipase molecules in cell walls. The best carbon source for extracellular lipase production by Y. lipolytica KKP 379 was olive oil. Glucose, dodecane and olive oil had a positive effect on biomass yield. Dodecane and/or glycerol utilization in microbiological lipase production was possible, but this process could not proceed without the addition of some activators such as olive oil in the cultivation medium.

The catalytic effect of baker's yeast on the hydrolysis of aliphatic esters in p-acetoxybenzoates is described. The chemoselective character of this reaction enables the selective protection of the hydroxyl group in p-hydroxybenzoic acid derivatives.

Increase in energy demand and limited sources of fossil fuels force the world’s population to seek new energy sources Biodiesel obtained by transesterification of oils with an alcohol in the presence of catalysts is an example of renewable fuel. The aim of the study was to assess the best conditions for enzymatic biodiesel synthesis by direct transesterification of rapeseed cake using Taguchi method. The influence of alcohol (methanol, ethanol, propanol, and butanol), temperature (30–60 °C), C. antarctica lipase B concentration (0.5–2 %), time (6–48 h) and rapeseed cake to alcohol ratio (1:2–1:5) was examined in the synthesis of fatty acid alkyl esters. Optimum conditions for direct enzymatic transesterification of rapeseed cake are: 30 °C, 12 h, 0.5 % of lipase and ethanol in 4:1 ratio to rapeseed cake.