A screening of endophytic fungi isolated from Mediterranean plants rendered a mycelium-bound lipase from a strain of Rhizopus oryzae that catalyzed the esterification of fatty acids in isooctane. The influence of various factors (water content, temperature, and pH) on ester synthesis was investigated. Catalytic activity was inversely correlated with water content. This enzyme was active over the entire pH range studied, from pH 3 to pH 8, and activity was maximal at pH 4 and pH 7. The enzyme was thermostable, with maximal activity at 60 degrees C.

No abstract

The compound 2,5-di(hydroxymethyl)furan (DHMF) is a high-value chemical block that can be synthesized from 5-hydroxymethylfurfural (HMF), a platform chemical that results from the dehydration of biomass-derived carbohydrates. In this work, the HMF biotransformation capability of different Fusarium species was evaluated, and F. striatum was selected to produce DHMF. The effects of the inoculum size, glucose concentration and pH of the media over DHMF production were evaluated by a 23 factorial design. A substrate feeding approach was found suitable to overcome the toxicity effect of HMF towards the cells when added at high concentrations (>75 mM). The process was successfully scaled-up at bioreactor scale (1.3 L working volume) with excellent DHMF production yields (95%) and selectivity (98%). DHMF was purified from the reaction media with high recovery and purity by organic solvent extraction with ethyl acetate.

Corn kernels naturally contaminated with fumonisins B1 and B2 were steeped by dipping the whole kernels in either water or a 0.3% solution of sodium bisulphite (pH = 5.7) for 6, 12, 24, 36 and 48 h. The toxin content of both the solid and the liquid were analysed for each time period. A different rate of interchange between the solid matrix and the water solution was found for FB1 and FB2 and some differences were found in the fate of both fumonisins between the two steeping systems studied. In addition, a preliminary study of the distribution of FB1 and FB2 between the germ and the remaining part of the kernel was carried out.

A total of 147 Fusarium spp., predominantly from the section Liseola were isolated from cereals in Catalonia, Spain. Fusarium moniliforme was the predominant species (85.7%) isolated from these grains. Other species·included Fusarium sporotrichoides, Fusarium heterosporum, Fusarium tricinctum, Fusarium poae, Fusarium anthophilum and Fusarium subglutinans. The ability of these isolates and species to produce fumonisin B1 and B2 was assessed on moist sterile corn. This showed that about 34% of the strains from the section Liseola produced both fumonisin B1 and B2 although the quantities varied considerably. One isolate of F. subglutinans was demonstrated to produce both fumonisin B1 and B2.

No abstract

The natural occurrence of fumonisins B, and B2, the incidence of Fusarium organisms, and the capacity of Fusarium isolates to produce fumonisins were investigated with 50 corn-based samples from Spain destined for human consumption. Eight samples (16%) were found to be contaminated with fumonisins. The levels of contamination were very low, with a mean of 80 ng/g.

Preparation of (S)-1-chloro-2-octanol and (S)-1-bromo-2-octanol was carried out by the enzymatic hydrolysis of halohydrin palmitates using biocatalysts. Halohydrin palmitates were prepared by various methods from palmitic acid and 1,2-octanediol. A tandem hydrolysis was carried out using lipases from Candida antarctica (Novozym® 435), Rhizomucor miehei (Lipozyme IM), and “resting cells” from a Rhizopus oryzae strain that was not mycotoxigenic. The influence of the enzyme and the reaction medium on the selective hydrolysis of isomeric mixtures of halohydrin esters is described. Novozym® 435 allowed preparation of (S)-1-chloro-2-octanol and (S)-1-bromo-2-octanol after 1–3 h of reaction at 40 °C in [BMIM][PF6].