Detection of β-galactofuranosidase production by Penicillium and Aspergillus species using 4-nitrophenyl β-D-galactofuranoside

An assay was developed for detecting β-galactofuranosidase produced by Penicillium and Aspergillus spp. The substrate for the assay, 4-nitrophenyl β-D-galactofura-noside, was synthesized from penta-O-acetyl-β-D-galactofuranose and 4-nitrophenol by a tin chloride catalyzed reaction followed by O-deacetylation. Aspergillus spp. produced only small quantities of β-galactofuranosidase during 30 d at 25°C. Only the biverticillate Penicillium spp. ( P. funiculosum, P. islandicum, P. rubrum and P. tardum ) produced substantial β-galactofuranosidase after 1–4 weeks at 25°C. No extracellular antigens of these four Penicillium spp. could be detected in culture filtrates by the sandwich ELISA technique when antibodies to the extracellular β-galactofuranoside-containing polysaccharide antigen of P. digitatum was used. Antigens to all other Penicillium and Aspergillus spp. were easily detected in their culture filtrates.     

Enzymes produced by <Emphasis Type="Italic">Ganoderma australe</Emphasis> growing on wood and in submerged cultures

Enzymes produced by Ganoderma australe in solid-state fermentation and submerged cultures were evaluated. Strain A464 produced laccase activity in liquid medium and in solid-state cultures containing Drimys winteri or Eucalyptus globulus wood chips, while MnP and LiP activities were not detected. On the other hand, strain A272 cultured for 75 days on E. globulus presented MnP activity of 719 IU/kg of wood. The suitability of D. winteri wood as a substrate enabling MnP production was checked with a well-documented MnP-producing basidiomycete, Ceriporiopsis subvermispora, which produced MnP activity of 327 IU/kg of wood in 9-day-old cultures. Data from two different G. australe strains (A272 and A464) indicated that MnP secretion depended on strain origin as well as on culture conditions.     

Production of enzyme preparations on the basis of Penicillum canescens recombinant strains with a high ability for the hydrolysis of plant materials

An enzyme preparation has been produced on the basis of Penicillium canescens strains with the activity of cellibiohydrolase I, II; endo-1,4-beta-gluconase of Penicillium verruculosum; and beta-glucosidase of Aspergillus niger. It was shown that for the most effective hydrolysis of aspen wood pulp the optimal ratio of cellobiohydrolase and endo- 1,4-3-gluconase in enzyme preparations was 8 : 2 (by protein). It was also established that the homologous xylanase secreted by the Penicillium canescens fungus is a required component for the enzyme complex for hydrolysis of the hemicellulose matrix of aspen wood.     

Mouse Genital Ridges in Organ Culture: The Effects of Temperature on Maturation and Experimental Induction of Teratocarcinogenesis

Abstract. Testicular teratomas can be induced experimentally by grafting genital ridges from male mouse fetuses to the testes of adults. A high incidence of teratomas occurs in genital ridges grafted to scrotal testes, but not in genital ridges grafted to testes maintained at body temperature. Genital ridges were cultured at 32° C or 37° C prior to grafting to the testes to determine the effect of temperature on the incidence of teratomas. Genital ridges cultured at 32° C for two or three days produced a high incidence of teratomas when grafted to the testes, in contrast to genital ridges cultured at 37° C for two or three days which produced a low incidence. Histologically, genital ridges cultured at 32° C contained disorganized testicular tubules and were retarded in development. Genital ridges continued to develop in vitro at 37° C, but were histologically different from genital ridges maturing in the fetus. Genital ridges cultured at 32° C for 10 to 12 days did not develop teratomas in vitro or after grafting to the testes. Further characterization of temperature effects in vitro may lead to a better understanding of teratocarcinogenesis in vivo.     

Extraction of xylans from hardwood chips prior to kraft cooking

The aim of this work is to define an extraction process of hemicelluloses from hardwood chips, prior to their transformation into paper pulp by the kraft process. Eucalyptus wood chips were submitted to autohydrolysis and acid hydrolysis treatments. Autohydrolysis means that no extra acid is added during the heating of the wood suspension, whereas sulphuric acid is added for the acid hydrolysis treatment. The liquor to wood ratio was 4, and temperature and time were varied so as to optimise the hemicelluloses extraction. Quantities of xylans varying between 12 and 38 g/l of hydrolysate (or between 9 and 15% on wood) could be extracted.Kraft cooking process was applied to the pre-hydrolysed wood chips. It was shown that they were easier to delignify than untreated wood chips, and the resulting pulp was also easier to bleach. The resulting cellulosic fibres were characterised for their papermaking properties: the higher the pentosan removal, the lower the strength properties of the pulps produced.     

Decolourization of reactive azo dyes with microorganisms growing on soft wood chips

The decolourization of a mixture of 200 mg L⁻¹ each of Reactive Black 5 and Reactive Red 2 dye was studied in batch experiments using microorganisms growing on forest residue wood chips in combination with or without added white-rot fungus, Bjerkandera sp. BOL 13. The study was performed as a first stage in the development of a relatively simple treatment process for textile wastewater, designed to work in developing countries. Forest residue wood chips contain a mixture of fungi and bacteria which is an advantage when complex molecules should be degraded. The wood chips furthermore provide the microorganisms with carbon source which make the addition of e.g. glucose unnecessary. The results showed that the microorganisms growing on the forest residue wood chips decolourized the mixture of the two dyes; adding extra nutrients approximately doubled the decolourization rate. The time needed for decolourization was approximately 18 days when nutrients were added. Lignocellulosic material is complex and so were the analysis, microorganisms were therefore transferred to ordinary soft wood chips from forest residue wood chips. Decolourization was measured with spectrophotometer and in order to determine intermediates HPLC was used.     

Production of enzyme preparations on the basis of Penicillum canescens recombinant strains with a high ability for the hydrolysis of plant materials

An enzyme preparation has been produced on the basis of Penicillium canescens strains with the activity of cellibiohydrolase I, II; endo-1,4-β-gluconase of Penicillium verruculosum; and β-glucosidase of Aspergillus niger. It was shown that for the most effective hydrolysis of aspen wood pulp the optimal ratio of cellobiohydrolase and endo-1,4-β-gluconase in enzyme preparations was 8: 2 (by protein). It was also established that the homologous xylanase secreted by the Penicillium canescens fungus is a required component for the enzyme complex for hydrolysis of the hemicellulose matrix of aspen wood.     

Influence of substrate wood-chip particle size on shiitake (Lentinula edodes) yield

Wood chips from four commercial hardwood sawmills were screened with 10 US standard sieves (4-0.21 mm) to assess particle size distributions. 96-98% of wood chips were < 4 mm while 95-99% of particles were > 0.21 mm. The majority (mean = 64.5%) of wood chips passed through US standard sieve size 14 (< 1.4 mm). Shiitake (Lentinula edodes) was grown in three crops to determine the effect of four particle size classes (1 = 2.8-4 mm; 2 = 1.7-2.8 mm; 3 = 0.85-1.7 mm; 4 = < 0.85 mm) on mushroom yield. Yields from substrates prepared with wood chips from class 4 (< 0.85 mm) were lower by 27.7%, 12.4% and 2% (mean = 14.9%) for Crops I, II, and III, respectively, when compared to controls. Profiling of wood chips may help growers optimize their production media and reduce production costs.     

Expression of SEF17 fimbriae by Salmonella enteritidis

M. DIBB-FULLER, E. ALLEN-VERCOE, M. J. WOODWARD AND C. J. THORNS. 1997. Specific immunological reagents were used to investigate the expression of SEF17 fimbriae by cultured strains of Salmonella enteritidis . Most strains of Salm. enteritidis tested expressed SEF17 when cultured at temperatures of 18–30°C. However, two wild-type strains produced SEF17 when also grown at 37 °C and 42 °C. Colonization factor antigen agar was the optimum medium for SEF17 expression, whereas Drigalski and Sensitest agars poorly supported SEF17 production. Very fine fimbriae produced by a strain of Salm. typhimurium were specifically and strongly labelled by SEF17 monoclonal and polyclonal antibodies, indicating considerable antigenic conservation between the two. Curli fimbriae from Escherichia coli were similarly labelled. The production of these fimbriae corellated with the binding of fibronectin by the organism. Congo red binding by cultured bacteria was not a reliable criterion for the expression of SEF17 fimbriae.     

Bioorganosolve pretreatments for simultaneous saccharification and fermentation of beech wood by ethanolysis and white rot fungi

Ethanol was produced by simultaneous saccharification and fermentation (SSF) from beech wood chips after bioorganosolve pretreatments by ethanolysis and white rot fungi, Ceriporiopsis subvermispora, Dichomitus squalens, Pleurotus ostreatus, and Coriolus versicolor. Beech wood chips were pretreated with the white rot fungi for 2-8 weeks without addition of any nutrients. The wood chips were then subjected to ethanolysis to separate them into pulp and soluble fractions (SFs). From the pulp fraction (PF), ethanol was produced by SSF using Saccharomyces cerevisiae AM12 and a commercial cellulase preparation, Meicelase, from Trichoderma viride. Among the four strains, C. subvermispora gave the highest yield on SSF. The yield of ethanol obtained after pretreatment with C. subvermispora for 8 weeks was 0.294 g g(-1) of ethanolysis pulp (74% of theoretical) and 0.176 g g(-1) of beech wood chips (62% of theoretical). The yield was 1.6 times higher than that obtained without the fungal treatments. The biological pretreatments saved 15% of the electricity needed for the ethanolysis.     

Hemicellulase activity of antarctic microfungi

The mannanase (endo-β-1,4-mannanase; E.C. 3.2.1.78) and xylanase (endo-β-1,4-xylanase; E.C. 3.2.1.8) activity of five microfungal isolates from Antarctica were characterized at different temperatures and pH. In general, the hemicellulase activity of the antarctic strains occurred at least 10 °C and as much as 30 °C lower than that of a mesophilic reference strain. At 0 °C, two strains, a Phoma and a Penicillium , produced in excess of 40% of their measured maximum activity of mannanase. All strains had maximum hemicellulase activity in the range pH 4–5, with Penicillium , Phoma and Alternaria strains exhibiting high (in excess of 80% of maximum) mannanase activity at pH 10. Three of the antarctic isolates exhibited high levels of xylanase activity over a pH range of 3–11.     

Control of root and shoot-bud formation from potato tuber tissue cultured in vitro

Comparative studies on the control of root and shoot-bud formation and plant regeneration have been undertaken in discs (1 × 6 mm in diameter) excised from tubers of potato ( Solanum tuberosum L. cv. Irish Cobbler) cultured in vitro. The results clarified that the optimal culture conditions for shoot-bud formation were quite different from those for root formation and, in conclusion, that (1) shoot-buds were produced when cultured in modified White's medium containing 0.25 M mannitol with 2.3 μ M zeatin and 0.57 μ M indole-3-acetic acid (IAA) at 20°C under relatively high light irradiation, while (2) roots were readily formed when cultured in modified White's medium containing 29 m M sucrose with 4.7 μ M kinetin plus 1.7 μ M IAA at 30°C in darkness.     

Removal of CCA from treated wood by oxalic acid extraction, steam explosion, and bacterial fermentation

Most preservative-treated wood produced and consumed in the United States is treated with toxic inorganic compounds containing copper, chromium, and arsenic. Because chromated copper arsenate (CCA) is fixed to the wood, CCA-treated wood has not been considered toxic or hazardous and it is currently disposed of in approved landfills. Growing public concern about environmental contamination from treated wood combined with the removal of greater quantities of CCA-treated wood from service have presented a disposal challenge for this fiber source. In this study, CCA-treated wood was processed by acid extraction, steam explosion, and bacterial fermentation and evaluated for removal of copper, chromium, and arsenic. Copper was the easiest to remove by these treatments and chromium the most resistant to removal. Exposing CCA-treated wood to steady-state bacterial growth by continuous culture with Bacillus licheniformis CC01 did not enhance removal of CCA components compared to standard mixed culture when acid extraction preceded bacterial fermentation. Nor did steam explosion, alone or in conjunction with acid extraction and bacterial fermentation, enhance removal of CCA components; the chromium and arsenic components resisted removal. Grinding CCA-treated wood chips into 20-mesh sawdust provided greater access to and removal of CCA components by all processes. However, grinding the chips was unnecessary if they were treated with acid prior to bacterial fermentation. Extraction with oxalic acid as a precursor to bacterial fermentation with B. licheniformis CC01 removed 90% copper (CuO), 80% chromium (CrO₃), and 100% arsenic (As₂O₅) from treated chips. The combination of acid extraction and bacterial fermentation removed 80–100% of these metals from CCA-treated wood. Received 15 December 1997/ Accepted in revised form 08 March 1998     

Endophytic <Emphasis Type="Italic">Penicillium citrinum</Emphasis> Thom. from <Emphasis Type="Italic">Scoparia dulcis</Emphasis> Linn

Scoparia dulcis of Scrophulariaceae is an annual herb distributed through out the tropics. Penicillium citrinum was obtained from apparently healthy roots, stem, leaves and fruits of this plant. Callus and multiple shoots produced during micropropagation from various explants were also symptomless but showed occurrence of Penicillium citrinum when cultured in Murashige & Skoog liquid medium for the production of secondary metabolites.     

Sulfite pretreatment (SPORL) for robust enzymatic saccharification of spruce and red pine

This study established a novel process using sulfite pretreatment to overcome recalcitrance of lignocellulose (SPORL) for robust and efficient bioconversion of softwoods. The process consists of sulfite treatment of wood chips under acidic conditions followed by mechanical size reduction using disk refining. The results indicated that after the SPORL pretreatment of spruce chips with 8–10% bisulfite and 1.8–3.7% sulfuric acid on oven dry (od) wood at 180 °C for 30 min, more than 90% cellulose conversion of substrate was achieved with enzyme loading of about 14.6 FPU cellulase plus 22.5 CBU β-glucosidase per gram of od substrate after 48 h hydrolysis. Glucose yield from enzymatic hydrolysis of the substrate per 100 g of untreated od spruce wood (glucan content 43%) was about 37 g (excluding the dissolved glucose during pretreatment). Hemicellulose removal was found to be as critical as lignin sulfonation for cellulose conversion in the SPORL process. Pretreatment altered the wood chips, which reduced electric energy consumption for size reduction to about 19 Wh/kg od untreated wood, or about 19 g glucose/Wh electricity. Furthermore, the SPORL produced low amounts of fermentation inhibitors, hydroxymethyl furfural (HMF) and furfural, of about 5 and 1 mg/g of untreated od wood, respectively. In addition, similar results were achieved when the SPORL was applied to red pine. By building on the mature sulfite pulping and disk refining technologies already practiced in the pulp and paper industry, the SPORL has very few technological barriers and risks for commercialization.     

Recycling of wood chips and wheat dregs for sludge processing

A Buchner filtration study was conducted to investigate the effect on sludge dewatering of adding organic waste solids (wood chips or wheat dregs) to sludge after chemical preconditioning (with ferric chloride or alum). Increasing the dose of wood chips or wheat dregs enhanced sludge filtration performance and increased the energy content of the filter cake, but did not consistently increase the total filtrate removed. The additional filtrate removal was found to balance the inert solids load only when the chemical preconditioner used did not result in sufficient coagulation of the sludge and the skeleton builder dose was low (< or = 90%). Accordingly, various dose ranges of wood chips and wheat dregs are suggested for different sludge management schemes.     

Endoglucanase-producing fungi isolated from Cape Evans historic expedition hut on Ross Island, Antarctica

Early explorers of Antarctica's Heroic Era erected wooden buildings and brought large quantities of supplies to survive in Antarctica. The introduction of wood and other organic materials provided nutrient sources for fungi that were indigenous to Antarctica or were brought in with the materials and adapted to the harsh conditions. Seventy-two isolates of filamentous fungi were cultured on selective media from interior structural wood of the Cape Evans historic hut and 27 of these screened positive for the ability to degrade carboxymethyl cellulose (CMC). Four non-CMC-degrading isolates were added to a group of 14 CMC-degrading isolates for further study, and endo-1, 4-beta-glucanase activity was demonstrated in the extracellular supernatant from all of these 18 isolates when grown at 4 degrees C, and also when they were grown at 15 degrees C. Isolates of Penicillium roquefortii and Cadophora malorum showed preference for growth at 15 degrees C rather than 25 degrees C or 4 degrees C indicating psychrotrophic characteristics. These results demonstrate that cellulolytic filamentous fungi found in Antarctica are capable of growth at cold temperatures and possess the ability to produce extracellular endo-1, 4-beta-glucanase when cultured at cold and temperate temperatures.     

Lab and Bench-Scale Pelletization of Torrefied Wood Chips—Process Optimization and Pellet Quality

Combined torrefaction and pelletization is used to increase the fuel value of biomass by increasing its energy density and improving its handling and combustion properties. In the present study, a single-pellet press tool was used to screen for the effects of pellet die temperature, moisture content, additive addition, and the degree of torrefaction on the pelletizing properties and pellet quality, i.e., density, static friction, and pellet strength. Results were compared with pellet production using a bench-scale pelletizer. The results indicate that friction is the key factor when scaling up from single-pellet press to bench-scale pelletizer. Tuning moisture content or increasing the die temperature did not ease the pellet production of torrefied wood chips significantly. The addition of rapeseed oil as a lubricant reduced the static friction by half and stabilized pellet production; however, the pellet quality, strength, and density were negatively affected. The pellets produced from pine wood torrefied at 250 and 280 °C were shorter than pellets produced from untreated wood and their quality did not match conventional wood pellet standards. However, the heating value of the torrefied pellets was higher and the particle size distribution after grinding the pellets was more uniform compared to conventional wood pellets.     

A Note on the Identities of Organisms Causing Black Spot Spoilage of Meat

Four fungal species, Cladosporium cladosporioides, C. herbarum, Penicillium hirsutum and Aureobasidium pullulans were isolated from meat spoiled by black spot and shown to produce black spot colonies when inoculated on to sterile meat slices which were incubated at — 1°C. Penicillium hirsutum grew only on the meat surface but the other species penetrated into the tissues, apparently in response to arid conditions at the surface. It is clear from these observations that the traditional association of black spot spoilage with C. herbarum alone is incorrect.     

Separation of Fungal Propagules by Partition in Aqueous Polymer Two-Phase Systems

Conidia of Penicillium chrysogenum and Penicillium frequentans and sporangiospores of Rhizopus rhizopodiformis, Rhizomucor pusillus, and Mucor racemosus were subjected to partition in aqueous polymer two-phase systems. The partition behavior differed drastically between the conidia of the two Penicillium species and the sporangiospores of the three species of phycomycetes. This difference in partition behavior can be used for purification of fungi belonging to different taxonomical groups. P. frequentans was completely separated from M. racemosus by two extractions, whereas four extractions were needed to purify M. racemosus. This method was used on an air sample from a locality where wood fuel chips are handled. The conidia of the fungi Trichoderma viride and Rhizopus rhizopodiformis were removed completely by only two extractions.