Optimization of diterpenes bioconversion process by the fungus Cephalosporium aphidicola

Abstract

Parameters for a more efficient biotransformation of diterpene-like compounds by the fungus Cephalosporium aphidicola were established by carrying out microscale feedings at several conditions. Experiments were guided by thin layer chromatography and gas chromatography analysis. It was observed that the substrate should be added in ethanol at concentrations between 15 to 30 mg per 100 ml of medium. The extraction of the product showed to be more efficient when carried out from both mycelia and broth and using ethylacetate as the extracting solvent. The experiment should be stopped six days after feeding the substrate to the fungus for the best product yield.

Microbial Oxidation of (-)-α-pinene to Verbenol Production by Newly Isolated Strains

“…2 permits us to verify a reduction on substrate bioconversion after 9 days of reaction. Takahashi et al [32] show that this reduction can be related to a possible product metabolization. The substrate concentration reduced until the tenth day for induced and non-induced cells.…”

“…The literature points out that a common problem in the monoterpenes biotransformation is the toxicity of these compounds for the microorganisms [18][19][20][21][22][23][24][25][26][27][28][29][30][31][32][33]. To reduce this effect, the method of cell induction by the substrate has been employed, allowing the microorganism adaptation with lower amounts of substrate [33,34].…”

Isolation and Screening of Microorganisms for R-(+)-Limonene and (−)-β-Pinene Biotransformation

“…2 and 3 permit us to verify a reduction on substrate bioconversion after 7 and 8 days of reaction, respectively. Takahashi et al [33] show that this reduction can be related to a possible product metabolization. The substrate concentration diminushed until the tenth day for both substrates for induced and noninduced cells.…”

Novel agents for enzymatic and fungal hydrolysis of stevioside

“…Although the low yields of experiments for obtaining steviol (2), in some cases, recovery of stevioside (1) was high, implying that reaction yields can be improved, either by increasing the reaction time (27), altering chemical composition of the medium (24,35), changing a substrate feeding procedure (8) or by the use of reactors with controlled reaction conditions (18). On other hand, even methodologies leading to low yields of aglycons without side reactions are of huge interest since acidic conditions can not guarantee aglycon stability in some specific cases.…”