Control of cellulose hydrolysis by fungi

Summary The extent of filter paper degradation by extracellular preparations fromT. reesei and its mutants with a decreasing level of -glucosidase and an increasing level of endoglucanase has been determined. The ability to degrade cellulose is restricted by the level of endoglucanase and not by -glucosidase.     

An investigation into the 19-hydroxylation of androstenedione,cortexolone and progesterone by selected fungi

Summary An investigation was performed to recognise a fungus capable of 19-hydroxylating the steroids androstenedione, cortexolone and progesterone, in high yield with little or no side reactions. The fungi selected for study belong to a group which has been previously reported to possess 19-hydroxylation ability. Pellicularia filamentasa f. sp. microsclerotia IFO 6298 and P. filamentosa f.sp. sasakii IFO 5254 both 19-hydroxylated cortexolone, but 19-hydroxylated products were not detected using either androstenedione or progesterone as substrate. When 19-hydroxylating cortexolone, both strains of P. filamentosa produced 11-hydroxycortexolone as a by-product, but P. filamentosa f.sp. microsclerotia IFO 6298 was superior in terms of 19-hydroxylation and the relative amounts of the two products.     

Growth of selected fungi on leaf-protein supernatant

Summary Some 19 strains ofAspergillus niger,A. oryzae, andPaccilomyces spp. are tested for their ability to grow on the supernatant remaining after the expressed juice from sugar beet tops and meadow grass has been heat-treated to precipitate crude leaf protein, and supplemented as required by glucose or ammonium sulphate. With effective strains ofA. niger,A. oryzae,P. elegans orP. variotii and an optimized carbohydrate/nitrogen ratio, over 70% of the organic content of the supernatant is rapidly converted into mycelial biomass of high protein content.     

Decomposition and humification of plant residues by some soil fungi

Summary Decomposition and humification of powdered plant material ofLeptochloa fusca L. Kunth andSesbania aculeata Pers. by eight soil fungi was studied in pure culture. Maximum decomposition was caused bySporotrichum pruinosum, and maximum humification byStachybotrys atra. Significant differences were observed in some chemical and optical properties of humic compounds produced by these fungi.     

Biomass protein formation by filamentous fungi on woody substrates

Summary Growth and biomass protein formation by filamentous fungi grown on pretreated tropical woods of Mesta (Hibiscus cannabinus Linn.) and Subabul [Leucaena leucocephala (Lam.) de Witt] as well as their isolated hemicellulose and cellulose fractions have been studied. Penicillium janthinellum and Penicillium funiculosum produced a biomass having 20 to 30% crude protein when grown on either hemicellulose, while growth on pretreated (autoclaved in 1% NaOH) wood or isolated cellulose fractions was comparatively poor and crude protein content only 5 to 8% in the biomass.NCL Communication no.3550     

Removal of NH3-N from domestic waste water by fungi

Summary Nine species of fungi viz.,Aspergillus niger,A. flavus,A. terreus,Fusarium solani,Mucor sp.,Neurospora crassa,Penicillium janthinellum,Trichoderma harzianum andTrichothecium roseum were evaluated for their potential to remove NH₃–N from domestic waste water. Of the fungi tested,A. flavus was found to be the most effective in the removal of NH₃–N. Maximum reduction (92%) of NH₃–N by this organism was observed at pH 8.0 at 20°C.     

Production of D-xylanases by thermophilic fungi using different methods of culture

Summary Seven thermophilic strains of fungi were examined for their ability to produce D-xylanase in Liquid and solid-state fermentations. It was confirmed that the best producers of xylanase, among microorganisms used, wereH. Lanuginosa andS. thermophile in liquid fermentation, andT. aurantiacus andH. lanuginosa in solid-state fermentations. The higher productivity of xylanase, namely 18,72 IU/ml, was obtained in liquid culture ofH. lanuginosa. The pH and temperature optima of enzymes from liquid and solid-state cultures of fungi used were also presented.     

Ligninolytic properties of different white-rot fungi

Summary Seven white-rot fungi were examined for the production of ligninase, manganese peroxidase and laccase. All these enzymes were found inTrametes gibbosa andTrametes hirsuta. Only manganese peroxidase and laccase were produced byPycnoporus cinnabarinus,Coriolopsis polyzona,Stereum hirsutum,Dichomitus squalens andGanoderma valesiacum. All fungi decolorized Poly B-411 and Indulin AT plates with low-N medium. The differences in enzyme pattern indicate that different species of fungi may employ different modes of lignin metabolism.     

Bioconversion of sugarcane bagasse with white rot fungi

Summary Four cultures of white rot fungi were screened for their ability to degrade lignin and carbohydrates of sugarcane bagasse and their effect on changes inin vitro digestibility.Polyporus hirsutus534 degraded maximum lignin and carbohydrates accompanied with the highest increase in digestibility, but increase in nutrient availability was maximum withPleurotus sajorcaju (Z-6) due to lower dry matter loss during the process of fungal treatment. All the fungi tested exceptPolyporus caperatus Berk. degraded lignin more selectively than the other components of sugarcane bagasse.     

Occurrence of cyclosporins and cyclosporin-like peptolides in fungi

Apart from 17 previously listed fungal taxa producing cyclosporin A and its natural congeners B to Z, several additional and taxonomically diverse strains producing the single novel component [Thr², Leu⁵, Leu¹⁰]cyclosporin or cyclosporin-like peptolides (eg SDZ 214-103=[Thr², Leu⁵, D-Hiv⁸, Leu¹⁰]cyclosporin) have recently been described. We report here the isolation of two further and novel cyclosporins, [Thr², Leu⁵, Ala¹⁰]cyclosporin (2) and [Thr², Ile⁵] cyclosporin (3), from strains classified asAcremonium luzulae (Fuckel) W Gams andLeptostroma anamorph ofHypoderma eucalyptii Cooke & Harkn, respectively. In both new strains the usual pattern of cyclosporins A to Z is not found. The structure elucidations of2 and3 are based on NMR spectroscopy, and biological data (immunosuppressive activity, cyclophilin-binding affinity and antifungal effects) are presented.     

Identification of a novel gene family,paralogs of inhibitor of apoptosis proteins present in plants,fungi, and animals

Only few orthologs of animal apoptosis regulators have been found in plants. Recently, the ectopic expression of mammalian inhibitor of apoptosis proteins (IAPs) has been shown to affect plant programmed cell death. Here, we identified two novel proteins homologous to Arabidopsis thaliana IAP-like protein (AtILP) 1 and 2 by applying an improved motif searching method. Furthermore, homologs of AtILP1 were found to occur as a novel gene family in other organisms such as fungi and animals including Homo sapiens (HsILP1). Like baculovirus IAP repeats (BIRs) in IAPs, ILPs contain two highly conserved BIR-like domains (BLDs) with a putative C2HC-type zinc finger. Phylogenetic analyses indicated that ILPs are putative paralogs of IAPs. Homology modeling revealed that the three-dimensional structure of BLD in HsILP1 is similar to that of BIR. Transient expression of HsILP1 resulted in inhibition of etoposide-induced apoptosis in HEK293 and HeLaS3 cells. These findings suggest that ILPs are conserved in a wide range of eukaryotes including plants, and that their functions are closely related to those of IAPs.     

Biotransformations by microbial Baeyer-Villiger monooxygenases stereoselective lactone formationin vitro by coupled enzyme systems

Summary The regio- and stereoselective biotransformation of bicyclo (3. 2. 0) hept-2-en-6-one by the NADH-dependent Baeyer-Villiger monooxygenase from camphorgrownPseudomonas putida NCIMB 10007 has been shown to yield a chiral lactone not accessible by curently-used biocatalysts. The biotransformation can be conductedin vitro using two alternative coupled enzyme systems (alcohol dehydrogenase and monooxygenase: formate dehydrogenase and monooxygenase) within situ recycling of NAD⁺/NADH.     

Clonal propagation of Stevia rebaudiana Bertoni by stem-tip culture

Clonal propagation of Stevia rebaudiana has been established by culturing stem-tips with a few leaf primordia on an agar medium supplemented with a high concentration (10 mg/l) of kinetin. Anatomical examination has suggested that these multiple shoots originate from a number of adventitious buds formed on the margin of the leaf. Innumerable shoots can be obtained by repeating the cycle of multiple-shoot formation from a single stem-tip of Stevia. These shoots produce roots when transferred to a medium containing NAA (0.1 mg/l) without kinetin. The regenerated plantlets can be transplanted to soil.     

Partial delignification of unbleached kraft pulp with ligninolytic fungi

Summary Unbleached kraft pulp is partially delignified on incubation under specified conditions with ligninolytic fungi, thereby decreasing requirements for bleaching chemicals. Studies withPhanerochaete chrysosporium demonstrated important effects of nutrient nitrogen and molecular oxygen concentrations. Possible approaches to rate enhancement are suggested.     

The hydrolysis of bagasse hemicelluloses by selected strains of Cellulomonas

Summary The enhanced cellulolytic activity of a Cellulomonas mutant has been shown to apply also to its ability to hydrolyse xylan-containing hemicelluloses. The hydrolytic activity was directly proportional to the xylose content in the hemicellulose substrate.     

Biological oxidation of thianthrene,thioxanthene and dibenzothiophene by the thermophilic organismSulfolobus acidocaldarius

Summary Microbial oxidation of some model aromatic organic sulfur compounds such as thianthrene, thioxanthene and dibenzothiophene by the thermophilic organismSulfolobus acidocaldarius has been studied. Sulfate ions released as an oxidation product were measured to quantify the oxidations. The oxidation of the aforementioned refractory aromatic sulfur compounds byS. acidocaldarius may have applications in organic sulfur removal from hydrocarbon fuels such as coal and oil.     

Regeneration by somatic embryogenesis of triploid plants from endosperm of walnut,Juglans regia L. cv Manregian

Plants were regenerated by somatic embryogenesis from endosperm tissue of open-pollinated seeds of Juglans regia L. cv Manregian. These plants were obtained by growing endosperm tissue on media similar to those used for plant regeneration from walnut cotyledons (Tulecke and McGranahan 1985). The plants appear morphologically uniform and have a triploid chromosome number of 3n=48. Nine plants have been grown to a young sapling stage in soil. This embryogenic line from endosperm has been maintained in culture for two years by the process of repetitive somatic embryogenesis.     

Saccharification of sugar cane bagasse by an enzyme preparation fromCellulomonas: Resistance to product inhibition

Summary An enzyme preparation from aCellulomonas strain has been shown previously to be active in releasing reducing sugars from alkali pretreated sugar cane bagasse. This enzyme preparation has been demonstrated to be very resistant to end product inhibition by xylose, glucose, cellobiose and ethanol.     

Continuous product recovery by in-situ gas stripping/condensation during solvent production from whey permeate usingClostridium acetobutylicum

Summary The use of in-situ gas stripping for the removal of toxic butanol from a batch fermentation usingClostridium acetobutylicum P262 has been examined. A cold trap was used to recover the butanol. Significant increases in the lactose utilization rate and solvents productivity were obtained.     

Design of a defined medium for growth ofCorynebacterium glutamicum in which citrate facilitates iron uptake

Summary An improved minimal medium for growth ofCorynebacterium glutamicum has been designed. In particular,C.glutamicum's inefficiency in assimilating iron has been overcome by optimization of the synergistic effects of sodium citrate and ferrous sulfate on the growth rate.