Search PubMed⌕ Search

Biomedical subjects

R W Detroy

Publications and source records attributed to R W Detroy.

At least 19 recordsLinked to original sources
PubMed1983

Biomass conversion: fermentation chemicals and fuels.

Recent events clearly establish that petroleum can no longer be relied upon as a stable, economical raw material for energy and industrial chemicals. Plant biomass is currently being evaluated as a desirable alternative raw material to petroleum because of renewability and abundance. The most abundant form of biomass on the planet earth is lignocellulose which is composed of cellulose, hemicellulose, and lignin. An estimated 4 X 10(9) tons per year of cellulose alone is readily available for conversion to energy or feedstuffs. This article explores the current state of research on the transformation of cellulose, hemi-cellulose, and lignin by various microorganisms and the subsequent production of fuels and chemicals. Current research activities are covered including technologies available for the utilization of biomass, chemicals from fermentation processes, conversion of biomass to sugar, direct bioconversion to liquid fuels.

Biotransformation↗
PubMed1982

Continuous and static fermentation of glucose to ethanol by immobilized Saccharomyces cerevisiae cells of different ages.

Glucose was converted to ethanol by calcium-alginate-entrapped Saccharomyces cerevisiae NRRL Y-2034 cells that were 24, 48, 72, and 96 h old in continuous-flow and static repeated-batch fermentors. In general, older yeast cells were more efficient than younger ones. In most cases, the continuous fermentations were better than the static ones in producing maximum ethanol yields (5.11 g/10 g of glucose) over extended time periods. The best static fermentation (with 24-h-old cells) converted 100% of the glucose to ethanol for about 12 days, whereas the best continuous fermentation (with 96-h-old cells) converted 100% of the glucose for a remarkable period of about 3 months.

Ethanol↗
PubMed1978

Mycoviruses of Penicillium stoloniferum: influence of carbon-nitrogen nutrition upon replication.

Carbon-nitrogen ratio experiments indicate that limiting nutrition not only hinders Penicillium stoloniferum host proliferation but reduces total PsV-F and PsV-S virus replication. Results of C-N experiments show a pH-induced autolysis and virus release at minimal C levels. Maximal PsV-F levels and biomass were obtained with glucose and sucrose as C sources. Oleic acid also yielded high biomass and PsV-F yields. Yeast extract was an excellent N source; 2.83 g dry weight biomass and 87 A260 units PsV-F after 96 h of growth. Other nitrogen sources, including amino acids, supported only minimal growth and virus replication. The autolysis phenomenon is pH, not viral-induced. High C and N will support maximal growth and unrestricted virus replication with no cellular lysis. Under low C growth conditions, the replication of PsV-S is favored coupled with high pH and autolysis.

Amino Acids↗
PubMed1976

Patulin inhibition of mycovirus replication in Penicillium stoloniferum.

Penicillium stoloniferum NRRL5267 contains two electrophoretically distinct viruses (PsV-F and PsV-S). An in vivo system was developed to test whether a number of fungal metabolites had antiviral properties on PsV-F replication in O.erties on PsV-F replication in P. stoloniferum. Preliminary results indicated that the mycotoxin patulin can block mycovirus replication. Portions of 48 h mycelium were incubated in the presence of varying levels of patulin, and after an additional 48 h incubation, PsV-F content was measured in E260 units by polyacrylamide gel electrophoresis. Patulin at 11, 16 and 20 mug/mg dry wt mycelia blocked PsV-F replication 26, 61 and 71%, respectively, compared with untreated controls. At these levels, host biomass RNA and protein synthesis were minimally affected. No-proliferating fungal mycelium is capable of continued support of PsV-F replication, which is sensitive to patulin. Apparently, inhibitory doses of patulin stimulated PsV-S replication during this 48 h incubation. The preferential action of patulin may arise from metabolite binding to functional enzymes required for virus replication.

Dose-Response Relationship, Drug↗
PubMed1975

Penicillium stoloniferum virus: altered replication in ultraviolet-derived mutants.

Phenotypic mutants of the wild type of Penicillium stoloniferum NRRL5267 were obtained from conidia exposed to ultraviolet light for 60 min (10% survival). Virus content of the wild type and of nine phenotypic mutants was determined by polyacrylamide gel electrophoresis. Four mutants had no detectable Penicillium stoloniferum virus F (PsV-F), whereas the other five had levels of PsV-F in the mycelium similar to the wild-type strain. All nine mutants and the wild type had comparable levels of Penicillium stoloniferum virus S (PsV-S). Maximum virus levels occurred after 9 days of submerged culture in a 2% yeast extract-15% sucrose medium. Virus replication in the fungal host continued after protein, RNA and DNA synthesis levelled off. Virus levels ranged from 85 to 150 E-260 units (extinction units at 260 nm in I cm cell) per 4-7 to 5-3 g dry weight of mycelium for the mutant strains compared to 106 E-260 units per 4-2 g dry weight of the wild-type strain.

Color↗
PubMed1974

Penicillium stoloniferum virus: large-scale concentration and purification by polyethylene glycol.

An experimental procedure developed to concentrate fungal viruses from large volumes of homogenized mycelia with water-soluble polymers, such as polyethylene glycol, possesses advantages over more conventional methods. Concentration of the Penicillium stoloniferum fast-moving virus from mycelial homogenates after addition of polyethylene glycol was rapid and produced large quantities of pure virus.

Ammonium Sulfate↗
PubMed1973

Mycotoxin-producing strains of Penicillium viridicatum: classification into subgroups.

Fifty-two isolates of Penicillium viridicatum Westling were divided into three groups based on ability to produce ochratoxin and/or citrinin, color, growth rate, type of growth, odor, and isolation source. Members of group I resemble one of the representative strains of P. viridicatum described in the literature; those belonging to group II differ from group I strains in several characteristics; group III is a heterogeneous series of highly variable isolates. Although three subgroupings can be recognized, retention of all isolates in the species P. viridicatum is deemed most appropriate at this time. Spore macerates of all isolates were examined for virus-like particles but none were detected.

Caproates↗
PubMed1973

Virus particles from conidia of Penicillium species.

Virus particles and their component double-stranded ribonucleic acid (dsRNA) have been isolated from conidia and mycelia of certain Penicillium species. The conidia and mycelia of P. stoloniferum NRRL 5267 contained 75 and 85 mug of dsRNA/g (dry weight), respectively. Of the total dsRNA released from NRRL 5267 conidia, 10% was nonencapsulated. Conidia of P. brevi-compactum NRRL 5260 and P. chrysogenum Q-176 contained 2 and 120 mug of dsRNA/g (dry weight), respectively, whereas mycelium from the two species contained 3 and 95 mug of dsRNA/g (dry weight), respectively. No viruses were isolated from conidia or mycelia of P. stoloniferum NRRL 859. A method is described for disruption of both conidia and mycelia. The technique facilitates the isolation and characterization of fungal viruses and their component dsRNA and also potentiates surveying of fungal isolates for the presence of virus.

Electrophoresis, Polyacrylamide Gel↗