Poplar Sawdust Research Articles

Wood sawdust and wood originate materials as adsorbents for heavy metal ions

The abilities of different types of wood sawdust and wood originate materials for removing some toxic heavy metal ions from water were investigated. Sawdust of poplar, willow, fir, oak and black locust wood, pulp and Kraft lignin were used as adsorbents. The effects of contact time, pH, metal concentration and sawdust particle size on the removal of Cu(II) ions by poplar sawdust have been studied. Leaching from these adsorbents into water during adsorption was also investigated.

느타리버섯 봉지재배시 배지 살균 조건에 따른 균사생장 및 자실체 생육 비교

느타리버섯 봉지재배시 살균 온도 및 시간에 따른 배지의 pH와 수분함량 변화, 균사생장 및 자실체 생육 등을 비교한 결과를 보고하고자 한다. 본 시험의 품종은 춘추 느타리 2호와 수한느타리 1호이고 시험배지는 미루나무톱밥 + 폐면 + 비트펄프(40 : 40 : 20%, v/v)와 미루나무톱밥 + 면실피 + 비트펄프(40 : 40 : 20%, v/v)를 사용하였다. 살균 후 배지의 수분함량은 폐면 혼합배지는 저온 살균에서는 1.8% 증가한 반면 면실피 혼합배지는 저온 살균에서 4.1% 감소하였고, 상압 살균과 고압 살균처리는 거의 변화가 없었다. pH는 살균온도가 높을수록 감소량이 많아 저온 살균(<TEX>$60^{\circ}C$</TEX>, 12시간)에서는 거의 변화가 없었으나 상압 살균 (<TEX>$100^{\circ}C$</TEX>, 6시간) 보다 고압 살균 (<TEX>$121^{\circ}C$</TEX>, 90분)에서 감소량이 많았다. 균사배양 및 자실체 생육일수는 저온 살균에서 균사밀도는 가장 낮았으며 배양일수도 가장 길었다. 2주기까지의 수량은 춘추느타리 2호는 폐면 혼합배지의 저온 살균처리에서 가장 낮았으며 그 밖의 처리는 통계적 유의성은 없었고, 생물학적 효율은 면실피 혼합배지를 고압 살균했을 때 96.6%로 가장 높았다. 수한느타리 1호는 면실피 혼합배지의 상압 살균 처리에서 각각 수량 259.1g/pot, 생물학적 효율 94.9%로 가장 높았다. 또한 춘추느타리 2호는 균사 배양 완료 후 배지 경도와 수량과는 고도의 정의 상관관계이며 수한느타리 1호는 배지경도가 지나치게 낮거나 높으면 수량이 감소하는 경향이었다. The suitable sterilization conditions in pot cultivation of varieties of Chunchunutari-2-ho and Suhannutari-1-ho Pleurotus ostreatus were investigated. The substrate formulations for the cultivation consisted of 40% poplar sawdust, 40% waste cotton and 20% beet pulp (PWB), and 40% poplar sawdust, 40% cotton seed hull and 20% beet pulp (PCB). The increase in the sterilization temperature caused decrease in the pH of the substrate. The moisture content of PWB substrate increased by 1.8%, but that of PCB substrate decreased by 4.1 % after low temperature sterilization (<TEX>$12hr\;at\;60^{\circ}C$</TEX>). However, a little change in the sterilization at higher temperature (<TEX>$6hr\;at\;100^{\circ}C\;and\;90min\;at\;121^{\circ}C$</TEX>) did not alter the moisture content of both substrate appreciably. The duration of mycelial growth was longest and its density was lowest in low temperature sterilization (<TEX>$12hr\;at\;60^{\circ}C$</TEX>). The high pressure sterilization (<TEX>$90min\;at\;121^{\circ}C$</TEX>) of PCB substrate produced high yield (236.6 g/pot) and the highest biological efficiency (96.6%) for Chunchunutari-2-ho. On the contrary the high temperatures sterilization (<TEX>$6hr\;at\;100^{\circ}C$</TEX>) of PCB substrate resulted in the yield of 259.1 g/pot with the biological efficiency 94.9% for Suhannutari-2-ho.

느타리버섯 봉지재배시 첨가제 및 첨가량이 균사배양 및 자실체 생육에 미치는 영향

느타리버섯 봉지재배의 첨가제 및 첨가량에 따른 균사배양 및 자실체 생육특성을 비교하여 적정 배지를 개발하고자 기본배지로 미루나무톱밥과 야외발효를 한 폐면을 부피비로 동량 혼합한 후 첨가제는 미강, 비트펄프, 면실박을, 첨가량은 10, 20, 30%로 각각 혼합하여 시험한 결과 배지의 pH와 총탄소량은 처리별 큰차이 없으나 총질소량이 면실박 첨가구에서 높아 이에 따라 C/N율이 낮아졌다. 균사배양 완류 후 배지 경도는 미강 첨가구에서 <TEX>$22.9{\sim}37.9kg/cm^{2}$</TEX>로 가장 높았으나 비트펄프는 <TEX>$9.3{\sim}11.6kg/cm^{2}$</TEX>으로 낮았으며 첨가량이 많아짐에 따라 배양일수가 지연되었고 이에 따라 재배기간이 길었고, 비트펄프 첨가구에서 <TEX>$58{\sim}60$</TEX>일로 짧았으며, 면실박을 20% 이상은 혼합시 균사 배양과 자실체 발생은 되나 높은 질소량에 따른 낮은 C/N율로 자실체 생육이 이루어지지 않았다. 또한 1주기에 대한 2주기의 수확가능한 수확율은 비트펄프 첨가구에서 <TEX>$75{\sim}85%$</TEX>로 가장 높아 2주기까지 안정한 수확이 가능하였고 수량 및 생물학적효율은 비트펄프 20% 첨가시 가장 높았다. This study was carried to investigate suitable additive materials and its mixing ratio in pot cultivation of Pleurotus ostreatus. The main substrate for Pleurotus ostreatus cultivation was poplar sawdust plus with waste cotton at the ratio 1 : 1 (v/v). Using pot diameter and substrate weight were 12 cm and 1 kg/pot, respectively. The higher amount of additives resulted in higher total nitrogen content and C/N ratio of substrate also decreased according to increasing mixing ratio of additives. The supplementation of cotton seed flour more than 20% caused the failure of devolopment of fruit body. The hardness of substrate in supplementation of rice bran after mycelial growth was highest any other additives. The ratio of harvest was highest in supplementation of beet pulp, <TEX>$75{\sim}85%$</TEX>. The fruit bodies yield and biological efficiency of supplemented with 20% beet pulp were highest during second flush.

Sunflower Seed Hulls as Substrate for the Cultivation of Shiitake Mushrooms

Nutritive agar formulations with additions of poplar (Populus alba) sawdust, wheat (Triticum durum) bran, or milled sunflower (Helianthus annuus) seed hulls (SSH) were evaluated for mycelium cultivation of shiitake (Lentinula edodes), in petri dishes. Sawdust, 2, 3 and 4 g·L-1 (0.27, 0.40 and 0.53 oz/gal) added to MYA (malt, yeast extract and agar) medium did not improve the mycelium growth rate, while media that included 1, 2, and 3 g·L-1 (0.13, 0.27, and 0.40 oz/gal) wheat bran or 2, 3, and 4 g·L-1 (0.27, 0.40, and 0.53 oz/gal) milled SSH exhibited a significant increase in the mycelium growth rate, at 25 °C (77 °F). The use of SSH obtained directly from the oil industry was evaluated as a substrate for the cultivation of shiitake mushroom via synthetic logs in plastic bags. A linear growth test was used to previously assay the mycelium growth rate in substrate compositions with different contents of SSH, wheat bran, and poplar sawdust, at 25 °C. The largest mycelial growth rates were 2.75, 2.88, and 2.93 mm·d-1 (0.108, 0.113, and 0.115 inch/day) for the substrates formulated with 8 SSH: 2 wheat bran, 9 SSH: 1 poplar sawdust, and 8 SSH: 1 wheat bran: 1 poplar sawdust by weight, respectively. The synthetic logs showed a daily production rate of 2 kg shiitake/100 kg dry substrate for a 55 days cycle production with a simple formula containing 37.5% SSH, 0.5% calcium carbonate (CaCO3), 2% calcium sulfate (CaSO4), and 60% water. Addition of wheat bran to the SSH-based synthetic log produced no significant differences on biological efficiency, mushroom production, or productivity.

Efficacy of a hot washing process for pretreated yellow poplar to enhance bioethanol production.

Cost reductions for pretreatment and bioconversion processes are key objectives necessary to the successful deployment of a bioethanol industry. These unit operations have long been recognized for their impact on the production cost of ethanol. One strategy to achieve this objective is to improve the pretreatment process to produce a pretreated substrate resulting in reduced bioconversion time, lower cellulase enzyme usage, and/or higher ethanol yields. Previous research produced a highly digestible pretreated yellow poplar substrate using a multistage, continuously flowing, very dilute sulfuric acid (0.07% (w/v)) pretreatment. This process reduced the time required for the bioconversion of pretreated yellow poplar sawdust to ethanol. This resulted in a substantially improved yield of ethanol from cellulose. However, the liquid volume requirements, steam demand, and complexity of the flow-through reactor configuration were determined to be serious barriers to commercialization of that process. A reconfigured process to achieve similar performance has been developed using a single-stage batch pretreatment followed by a separation of solids and liquids and washing of the solids at a temperatures between 130 and 150 degrees C. Separation and washing at the elevated temperature is believed to prevent a large fraction of the solubilized lignin and xylan from reprecipitating and/or reassociating with the pretreated solids. This washing of the solids at elevated temperature resulted in both higher recovered yields of soluble xylose sugars and a more digestible pretreated substrate for enzymatic hydrolysis. Key operating variables and process performance indicators included acid concentration, temperature, wash volume, wash temperature, soluble xylose recovery, and performance of the washed, pretreated solids in bioconversion via simultaneous saccharification and fermentation (SSF). Initial results indicated over a 50% increase in ethanol yield at 72 h for the hot washed material as compared to the control (no washing, no separation) and a 43% reduction of in the bioconversion time required for a high ethanol yield from cellulose

Mycelium growth kinetics and optimal temperature conditions for the cultivation of edible mushroom species on lignocellulosic substrates.

The influence of environmental parameters on mycelial linear growth of Pleurotus ostreatus, P. eryngii, P. pulmonarius, Agrocybe aegerita, Lentinula edodes, Volvariella volvacea and Auricularia auricula-judae was determined in two different nutrient media in a wide range of temperature, forming the basis for the assessment of their temperature optima. V. volvacea grew faster at 35 degrees C, P. eryngii at 25 degrees C, P. ostreatus and P. pulmonarius at 30 degrees C, A. aegerita at 25 or 30 degrees C and A. auricula-judae at 20 or 25 degrees C depending on the nutrient medium used and L. edodes at 20 or 30 degrees C depending on the strain examined. The mycelium extension rates were evaluated on seven mushroom cultivation substrates: wheat straw, cotton gin-trash, peanut shells, poplar sawdust, oak sawdust, corn cobs and olive press-cake. The mycelium extension rates (linear growth and colonization rates) were determined by the 'race-tube' technique, and were found to be the highest on cotton gin-trash, peanut shells and poplar sawdust for Pleurotus spp. and A. aegerita. Wheat straw, peanut shells and particularly cotton gin-trash supported fast growth of V. volvacea, whereas wheat straw was the most suitable substrate for L. edodes and A. auricula-judae. Supplemented oak sawdust and olive press-cake were poor substrates for most species examined, while almost all strains performed adequately on corn cobs.

A Comparison of Aqueous and Dilute-Acid Single-Temperature Pretreatment of Yellow Poplar Sawdust

Pretreatment of fresh yellow poplar sawdust (<6 mm, 25−30 wt % moisture) with hot liquid water (190−220 °C, 2.0−7.5 min, 2−7 wt % solids loading) or steam (220 °C, 2.0 min) was compared with dilute acid pretreatment (0.8% w/v sulfuric acid, 175 °C, 10 min, 20−25 wt % solids loading). The most favorable conditions for hot liquid water pretreatment (220 °C, 2.0 min, 5 wt % solids loading) performed as well as the dilute acid pretreatment (175 °C, 10.0 min, 0.8% sulfuric acid, 20 wt % solids loading) for fermentation of the cellulosic fraction of the pretreated fibers by simultaneous saccharification and fermentation (SSF), using Saccharomyces cerevisiae and 25 IFPU cellulase/g of cellulose. Ethanol yields of 97 and 92 wt % of the theoretical yield and xylan recoveries of 85 and 70 wt % (92 and 96 wt % solubilization) were achieved with the hot liquid water and dilute acid pretreatments, respectively. Steam pretreatment (220 °C, 2 min) was not as effective as the dilute acid pretreatment, resulting in an eth...

Effects of humic substances from composted or chemically decomposed poplar sawdust on mineral nutrition of ryegrass

Two organic fertilizers were prepared from the same initial mixture of poplar sawdust, blood and flour either by composting in a reactor or by chemical oxidation. Both processes resulted in loss of c. 30% of the organic matter. Composting required 90 days in comparison to only a few hours with chemical oxidation. Extraction of the organic residues with 1 N KOH gave solutions containing 24·6 and 15·1 g/l of humic substances respectively. These humic solutions were applied to pot-grown Lolium multiflorum Lam. at 4 and 10 mg carbon per pot to assess the short-term uptake of macro and microelements by the plants. When the plants were short of phosphorus, the humic substances from the chemically decomposed sawdust supplied at 10 mg C per pot improved total P uptake and yield. Humic substances also increased copper and manganese uptake, and by enhancing root development, also improved nitrogen uptake and biomass yield.

Manganese Peroxidase Isoenzymes Produced by Pleurotus ostreatus Grown on Wood Sawdust

The white rot basidiomycete Pleurotus ostreatus produces two manganese peroxidase (MnP) isoenzymes when grown in solid stationary conditions on poplar sawdust, whereas a lower production of these same enzymes is observed on fir sawdust. Addition of Mn2+ to poplar culture resulted in a threefold increase of MnP activity; the same addition to fir culture was able to increase tenfold the MnP production. The two MnP isoenzymes (MnP2 and MnP3) were purified from P. ostreatus poplar culture. The isoenzymes differ in their pI values, molecular masses, and N-terminal sequences. MnP3 has the same N-terminal sequence as that of a P. ostreatus MnP previously reported. Both isoenzymes exhibit Mn2+-dependent and Mn2+-independent peroxidase activities when tested on phenolic substrates. The gene coding for the new isoenzyme MnP2 was cloned and sequenced and the promoter region analyzed. Furthermore, the chromosomal localization of all known P. ostreatus genes was determined.

Enzyme Production, Growth, and Adaptation of T. reesei Strains QM9414, L-27, RL-P37, and Rut C-30 to Conditioned Yellow Poplar Sawdust Hydrolysate(Scientific Note)

National Renewable Energy Laboratory (NREL) has developed a conditioning process that decreases acetic acid levels in pretreated yellow poplar hydrolysate. Trichoderma reesei is sensitive to acetic acid and this conditioning method has enabled applied cellulase production with hardwoods. T. reesei strains QM9414, L-27, RL-P37, and Rut C-30 were screened for growth on conditioned hydrolysate liquor. Tolerance to hydrolysate was found to be strain-dependent. Strain QM9414 was adapted to grow in 80% (v/v) conditioned hydrolysate (40 g/L of soluble sugars and 1.6 g/L acetic acid from pretreated poplar). However, enzyme production was highest at 20% (v/v) hydrolysate using strain L-27. Cellulase titers of 2-3 International Filter Paper Units (IFPU)/mL were achieved using pretreated yellow poplar liquors and solids as the sole carbon sources.

Pretreatment of yellow poplar sawdust by pressure cooking in water

The pretreatment of yellow poplar wood sawdust using liquid water at temperatures above 220°C enhances enzyme hydrolysis. This paper reviews our prior research and describes the laboratory reactor system currently in use for cooking wood sawdust at temperatures ranging from 220 to 260°C. The wood sawdust at a 6–6.6% solid/liquid slurry was treated in a 2 L, 304 SS, Parr reactor with three turbine propeller agitators and a proportional integral derivative (PID) controller, which controlled temperature within ±1°C. Heat-up times to the final temperatures of 220, 240, or 260°C were achieved in 60–70 min. Hold time at the final temperature was less than 1 min. A serpentine cooling coil, through which tap water was circulated at the completion of the run, cooled the reactor’s contents within 3 min after the maximum temperature was attained. A bottoms port, as well as ports in the reactor’s head plate, facilitated sampling of the slurry and measuring the pH, which changes from an initial value of 5 before cooking to a value of approx 3 after cooking. Enzyme hydrolysis gave 80–90% conversion of cellulose in the pretreated wood to glucose. Simultaneous saccharification and fermentation of washed, pretreated lignocellulose gave an ethanol yield that was 55% of theoretical. Untreated wood sawdust gave less than 5% hydrolysis under the same conditions.

Optimization of reverse-flow, two-temperature, dilute-acid pretreatment to enhance biomass conversion to ethanol

A reverse-flow, two-temperature dilute-acid prehydrolysis process of commercial yellow poplar sawdust using two percolation reactors was designed to simulate countercurrent flow of the biomass solids and prehydrolysis liquor, and to exploit the xylan biphasic kinetics. Lower temperatures (150–174°C) are initially applied to hydrolyze the easily hydrolyzable xylan, and higher temperatures (180–204°C) are applied to hydrolyze the remaining xylan. Two reactors were used to optimize each temperature range, using varying concentrations of sulfuric acid from 0.073–0.73 wt% and reaction times. Yields of soluble xylose, as high as 97% of theoretical, expressed as monomeric and oligomeric xylose, have been achieved with only 2.9% of the xylan being degraded to furfural, at concentrations of total potential sugar between 2.4 and 3.7 wt% before flashing. Depending on the combined severity of the acid concentration, residence time of the solids and liquor, and temperature of prehydrolysis, 81–100% of the hemicellulose, 3–32% of the glucans, and up to 46% of the Klason lignin could be solubilized. The lignocellulosic substrate produced from the pretreatment is readily converted to ethanol at a yield of approx 91% of theoretical, with ethanol concentrations of up to 4.0 wt% in 55 h via a simultaneous saccharification and fermentation (SSF) process. In terms of xylose recovery and ethanol production level and rate, the present results are far superior to those previously reported using a single-temperature, dilute-acid pretreatment.

Association of Bacillus thuringiensis and Other Spore-Forming Bacteria with Calf-Hutch Bedding

Acetate selection and biochemical tests were used to characterize the gram positive, spore-forming bacteria associated with samples of straw and sawdust used as bedding in outdoor calf hutches. Bedding samples were collected from 25 calf-occupied hutches during 6-wk periods. More than 7,100 isolates representing Bacillus thuringiensis (4,616), Bacillus sphaericus (1,390), and Bacillus megaterium (1,182) were recovered. Fourteen biochemical types of B. thuringiensis were identified; these included galleriae, kurstaki, thuringiensis, israelensis, sotto, darmstadiensis, tenebrionis/morrisoni, dendrolimus , and indiana . Of these, tenebrionis/morrisoni and israelensis were associated most often with tulip poplar and maple sawdusts, respectively. Tulip poplar sawdust supported more diverse B. thuringiensis biochemical types than other types of sawdust or straw. B. thuringiensis were prevalent in calf-hutch bedding throughout 6-wk periods.

Enhancement of Poplar Cellulose Susceptibility to Cellulase Enzyme Hydrolysis by Ozonation

Abstract Treatment of poplar sawdust with ozone in a fixed bed reactor results in greatly enhanced susceptibility to cellulase enzyme hydrolysis. Ozone attacks lignin and hemicellulose in preference to cellulose giving water soluble products.

Aerobic nitrogen fixation during the biodegradation of lignocellulosic wastes

The detailed analysis of the changes in pH, CO 2 production, water content and organic matter decomposition showed the occurrence of an alternate succession of intense microbiological activity stages and stationary periods during the aerobic degradation of various lignocellulosic wastes (poplar sawdust, wheat straw and sawdust-straw mixture) in reactors at room temperature over several months. The total nitrogen content followed the same general pattern of change. Dinitrogen fixation occurred during short periods when low molecular weight carbon compounds released through lignocellulose hydrolysis were available to N 2-fixers under conditions of severe mineral nitrogen deficiency. The overall nitrogen enrichment could reach values of 8 g kg −1 initial dry matter. The action of the various successive microbial (saprophytic and N 2-fixing) populations was both complementary and competitive. Asymbiotic nitrogen fixation was promoted by pH values close to neutrality and irreversibly inhibited by acidity. An initial input of urea speeded up sawdust decay and promoted N 2 fixation later on. Substrate-enrichment in molybdenum enhanced N 2 fixation: the yield, expressed as mg fixed N 2 per g CO 2 evolved, reached its highest values (60% of the maximum theoretical yield) at low Mo concentrations (20 ppm) whereas toxic doses were particularly high (2000 ppm).

Ozonolysis of lignin — Improvement of in vitro digestibility of poplar sawdust

Conditions for optimal digestion of poplar sawdust using ozonolysis were investigated in both a fixed bed reactor and a stirred semibatch reactor. The fixed reactor performed better than the batch reactor. Of the parameters studied, (moisture content of the sample, particle size and ozone concentration in the gas flow), the moisture content of the sawdust had the most significant effect on solubilization. Digestibility was estimated by treating the ozonized samples with cellulose from Trichoderma reesei. Ozone treatment increased accessibility of the enzyme to the substrate.

Optimization of In-vessel Co-composting through heat recovery

A deliberate heat removal strategy based on temperature and oxygen consumption feedback control during the thermophilic stage was applied to composting mixtures (32% sewage sludges, 8% flotation foams and 60% poplar sawdust) in an insulated and unheated reactor using a water jacket as a thermal exchanger. Heat removal, under adequate conditions, does not modify the yield of the composting process although it is speeded up: the decomposition rate of organic matter was close to 20% and the fats were nearly completely (85%) degraded. The oxygen consumption rate versus temperature plot was characterized by the occurrence of an optimum around 65°C. The thermal balance showed that the total energy output within 1 week was close to 1000 kcal kg −1 dry matter and that the largest part of the thermal energy released could be assigned to the degradation of the fats.

Autohydrolysis extraction process as a pretreatment of lignocelluloses for their enzymatic hydrolysis

AbstractAutohydrolysis was studied as a pretreatment to enhance sugar yields from enzymatic hydrolysis of wheat and rape straw, beech, birch and poplar sawdust. Reaction temperatures were 185°C to 212°C and the reaction time 20 min. The pretreated slurries were hydrolyzed with “Novo” cellulase and Fusarium sp. 27 cellulase at 45°C and pH 4.8 for 24 h with addition of Fusarium sp. 27 cellbound cellobiase. From 85% to 90% sugar content of substrates were converted to reducing sugars after 24 h enzymatic hydrolysis, with exception of poplar wood.10.8 g biomass was obtained after cultivation of Fusarium sp. 27 with water solution hemicellulose fraction from 100 g beech sawdust autohydrolyzed at 200°C during 20 min.

Changes in Cell Size and Nuclear Number During Elongation ofFlammulina VelutipesFruitbodies

SUMMARY Flammulina velutipes fruitbodies were grown on nutrient-supplemented poplar sawdust. Cells in the middle and tip of the stipe became longer with increasing fruitbody length, but cells at the base ceased to elongate when fruitbodies reached 2-3 cm. Cell width also increased in elongating stipes. Elongation of cells of the middle region accelerated at the onset of rapid stipe growth, continued at maximum rate (110 /m/day) for three-quarters of that phase, and had almost ceased when the rate of stipe growth declined. Cells in the apical region of the stipe elongated at only about one-seventh the rate of the middle cells during rapid stipe elongation. The stipe growth zone reached its maximum length during the latter phase of rapid stipe elongation, and then became shorter and restricted to the upper stipe. Cell elongation in the middle and upper middle stipe regions accounted for most of the stipe elongation but this was accompanied by cell divisions. The number of stipe cells in a row almost quadrupled between the primordium stage and the onset of rapid elongation and increased by 40% thereafter. Stipe and pileus cells were usually binucleate in primordia. Subsequently, cells of the stipe and pileus context became multinucleate but those of the lamellar trama remained binucleate. The number of nuclei in stipe cells almost doubled during early fruitbody development, and increased to a mean of 9.1-9.2 in the middle and tip cells during rapid stipe elongation. In basal cells the nuclear number reached its maximum before the onset of rapid growth. No correlation was found between nuclear number and cell size.