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.     

Electron flow shift inClostridium acetobutylicum fermentation by electrochemically introduced reducing equivalent

Electrochemical energy as a source of reducing equivalent was applied to the cultures ofClostridum acetobutylicum to understand the effects of the pressure by reducing equivalent on anaerobic bacteria. The fermentation byC. acetobutylicum with methyl viologen and electrochemical energy produced more butanol (up to 26%) than the control culture, whilst less acetone (up to 25%) was produced. But no effect was observed on the growth of the culture. These results were indirectly supported byin vitro electrochemical reduction of NAD⁺ and artificial electron carriers.     

Direct fermentation of cellodextrins to ethanol byCandida wickerhamii andC. Lusitaniae

Summary Production of ethanol from cellodextrins, as large as cellohexose, byCandida lusitaniae andC. wickerhamii was studied.C. lusitaniae fermented only glucose and cellobiose, whereasC. wickerhamii efficiently fermented cellodextrins. Maximum ethanol yields of 29.2 g/liter from 54 g/liter cellodextrins were achieved byC. wickerhamii in 3–4 days.     

Selection of preculture conditions for solid state fermentation of sugar beet pulp

Summary For the protein upgrading of sugar-beet pulp in solid state fermentation byTrichoderma reesei andFusarium oxysporum, serveral conditions were studied to prepare an economical preculture for large scale process. The best performance was shown by a preculture obtained in 24 h from 1.5 % molasses solution at pH 4.5–5.0 with 1.0 % milled beet pulp.     

Genetic transformation of a pasture legume,Lotus corniculatus,L. (birdsfoot trefoil)

Summary A rapid procedure for introducing foreign genes inLotus corniculatus based on the induction of hairy roots byAgrobacterium rhizogenes was developed. Expression of chloramphenicol acetyltransferase and neomycin phosphotransferase II was revealed in transgenic plants. Southern blot hybridization was used to confirm the genetic transformation. The transgenic plants looked normal and did not show any morphological modification compared to the seed grown plants.     

The effect of various peptones on the production of cephalosporin C byPaecilomyces persicinus P-10 M1

Summary A microfermentation procedure was employed to determine the effects of peptones on the growth ofPaecilomyces persicinus P-10 M1 and its synthesis of cephalosporin C. Of the peptones tested only papain digest of soy peptone supported the production of cephalosporin C byP. persicinus P-10 M1.     

Overproduction of human insulin-like growth factor-II inEscherichia coli

Summary Human insulin-like growth factor II (hIGF-II) was produced inEscherichia coli as a protein fused to human growth hormone. High level expression of the fusion protein was attained with pIBL-1 plasmid. The hIGF-II obtained byin vitro cleavage of the fusion protein with cyanogen bromide was highly purified and its biological activity was assessed.     

The metabolism of lactose byClostridium acetobutylicum

Summary Acetone and butanol biosynthesis byClostridium acetobutylicum ATCC 824 was affected by lactose concentration and by agitation during the fermentation. At 1% and 3% lactose concentrations acid production predominated, while butanol production predominated at 5% lactose concentration. Higher solvent production was observed in fermentors without agitation than in fermentors with agitation.     

Bdellovibrio in methylotrophic bacteria

Summary During the production of single cell protein ofMethylomonas sp. using methanol as the sole carbon source in the pilot plant scale, we isolated aBdellovibrio strain from an abnormal fermentation broth. The abnormality of fermentation caused byBdellovibrio was much like phage infection. However, the plaques formed byBdellovibrio enlarged progressively when plated with host.     

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.     

Solvent-induced inversion of enantiosflectivity in lipase-catalyzed esterification of 2-phenoxypropionic acids

Summary In the esterification of 2-phenoxypropionic acids catalyzed byCandida cylindracea lipase, its enantio-selectivity was inverted in non-polar solvents such as carbon tetrachloride from that in polar solvents such as acetone. A model for this inversion is suggested.     

Bacteriophage development in an immobilized lactic acid bacteria system

Summary Bacteriophages were added to milk fermented byStreptococcus raffinolactis cells immobilized in calcium alginate. Beads containing the immobilized streptococci were used for five consecutive fermentations; pH, free cell and bacteriophage counts were estimated. Free cells increased from 5×10⁶ to 3×10⁸ per mL of milk, over the successive fermentations. Addition of bacteriophages reduced the free cell count by almost 1000 after 3 fermentations, but a gradual increase occurred subsequently. Bacteriophages were inoculated at 100 per mL and gradually attained 5×10⁹ per mL in the system. Rinsing of the system did not have a substantial influence on free cell or phage counts. Presence of bacteriophage reduced slightly the acidification rate in the system.Bacteriophage numeration by two layer agar method gave better results than by most probable number (MPN). MPN counts were greatly influenced byS. raffinolactis inoculation level.Contribution # 099     

Silver toxicity to ferrous iron and pyrite oxidation and its alleviation by yeast extract in cultures ofThiobacillus ferrooxidans

Summary Ferrous-ion oxidation byThiobacillus ferrooxidans was inhibited by 10^–6 M Ag⁺ while a slight inhibition of growth was apparent with 10^–7 M Ag⁺. The threshold toxic concentration was the seme for four different test strains. While prolonged lag phases resulted from culture exposure to Ag⁺, Fe²⁺ oxidation rates after the onset of growth showed little variation under these conditions. Yeast extract (0.02%) partially alleviated the toxicity of silver-ion by reducing the lag periods. Pyrite oxidation byT. ferrooxidans and mixed cultures of acidophiles was tested at 8.3×10^–7 to 8.3×10^–5 M Ag⁺. Strong inhibition was apparent at 8.3×10^–5 M Ag⁺ and little to no inhibition was observed at 8.3×10^–7 M Ag⁺.     

Solid state fermentation and fractionation of oat straw by Basidiomycetes

Summary Seventee white-rot and brown-rot fungi were screened for their ability to fractionate the lignocellulose structure of oat straw through the preferential attack of lignin or cellulose. Fermentations were carried out under solid-state conditions with 25 g quantities of straw. The fermented straw was analyzed for weight loss, Klason lignin loss and cellulase digestion. All the fungi attacked both lignin and carbohydrate fractions causing 3–28% weight losses and 26–34 g/100 g enzymatic digestibility. Polyporus tulipiferae, Phanerochaete chrysosporium and Polyporus sp. were tested for the effects of various nitrogen, phosphate and carbon levels, incubation temperatures and incubation time. The three fungi had different responses to these factors.     

Correlation between limitation of growth ofPachysolen tannophilus on D-xylose with the formation of ethanol and other products

The formation of ethanol, xylitol, ribitol, arabitol and acetic acid from D-xylose byPachysolen tannophilus correlated with the limitation of growth. The correlation was consistent with these products being secondary metabolites.Issued as NRCC Publication Number 24259.     

Production of extracellular 5-aminolevulinic acid byClostridium thermoaceticum grown in minimal medium

Summary A growth associated formation of extracellular 5-aminolevulinic acid (ALA) was found in the homoacetogenesis of glucose byClostridium thermoaceticum grown in minimal defined medium. The growth and ALA production was enhanced by L-cysteine HCl both in complex medium (UM) and minimal defined medium (MDM). The amount of ALA produced extracellularly in MDM wasca. 15 mg/L after 90-h anaerobic cultivation (cell-mass: 1.5 g/l; glucose consumed: 20 g/l).     

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.     

Could the improvements in the alcoholic fermentation of high glucose concentrations by yeast immobilization be explained by media supplementation?

Summary The maximal concentration of ethanol produced during the fermentation of 320 g/l glucose bySaccharomyces bayanus was higher when the yeast cells were immobilized either by adsorption on celite or by entrapment in k-carrageenan beads (from 10.5% with free cells up to 14.5% and 13.1% (v/v) respectively). This increase was due to medium supplementation with the compounds present in the immobilization supports.     

Identification of a penicillin V acylase processing fungus

In our studies with the penicillin V acylase of Bovista plumbea strains NRRL 3501 and NRRL 3824, we wanted to receive spores of these fungi. Surprisingly the fruiting bodies obtained in our work were not identical with those characteristic for Bovista plumbea. We identified them as Pleurotus ostreatus. For this reason we have to correct the name of the fungi known as Bovista plumbea NRRL 3501 and NRRL 3824.     

In situ detection of transposition of the maize controlling element (Ac) in transgenic soybean tissues

The development of a transposon mutagenesis system in soybean would aid in the isolation of unknown genes. The maize controlling element (Ac) has, therefore, been introduced into the soybean (Glycine max (L.) Merr.) genome byAgrobacterium-mediated transformation.Ac was inserted into the untranslated leader region of the bacterial ß-glucuronidase gene (GUS) such that the excision ofAc resulted in restoration of the GUS gene activity. Excision events of theAc element were monitored by detecting blue cells or sectors in transgenic soybean tissues. Using the GUS gene assay and with hybridization data, we have demonstrated that theAc element transposes in transgenic soybean calli, leaves, stems, and roots.