Ground Cornstalks Research Articles

Biodegradable polymer composite containing ground corn stalk modified with polydopamine

AbstractModifying plant fibers before their incorporation into the polymer matrix is a crucial factor that influences the characteristics of the resulting composites. This article reports on a study that investigated how modifying ground corn stalks impacted certain properties of a biodegradable polymer composite. The composite was made up of a mixture of polylactide and polycaprolactone in a ratio of 70:30, and the filler was modified using dopamine hydrochloride to create a thin polymer layer of polydopamine on the surface of the particles. The study evaluated the structural, mechanical, thermal, and thermomechanical properties of composites that contained 30%, 40%, or 50% of the filler by weight. Additionally, the tests to determine how well the composites would compost in an industrial setting were conducted. The results of the study showed that modifying the filler particles had a positive impact on most of the properties tested, including tensile strength, flexural strength, Young's modulus, storage modulus, and impact strength. Interestingly, despite concerns about the antibacterial properties of polydopamine, the composting tests revealed that the modification of the filler particles did not have any negative effects on the industrial composting process.

Evaluation of Design Characteristics for Animal Mortality Composting Systems

HighlightsDesign characteristics for animal mortality compost cover materials were tested.Compressive stress was applied to simulate the effects of the mortalities on cover materials.The highest permeability was measured for sawdust at 25% moisture content.A linear relationship was found between the volumetric flow rate and the power required to aerate the piles.Abstract. Composting is an aerobic process that relies on natural aeration to maintain proper oxygen levels. Air-filled porosity, mechanical strength, and permeability are among the essential parameters used to optimize the process. This study’s objective was to measure the physical parameters and airflow characteristics of three commonly used cover materials at four moisture levels, which could be used in designing actively aerated swine mortality composting systems. A laboratory-scale experiment was conducted to measure pressure drops across the cover materials as a function of the airflow rate and the material’s moisture content. Compressive stress was applied for 48 h to simulate the impact of swine mortalities on the cover materials. The power required to aerate each material was determined as a function of volumetric flow rate and moisture content. As expected, air-filled porosity and permeability decreased with increasing bulk density and moisture content. The highest average permeability values were measured at 25% moisture content and ranged from 66 × 10-4 to 70 × 10-4 mm2, from 161 × 10-4 to 209 × 10-4 mm2, and from 481 × 10-4 to 586 × 10-4 mm2 for woodchips, ground cornstalks, and sawdust, respectively. For the range of airflow rates tested in this study (0.0025 to 0.0050 m3 s-1 m-2), a linear relationship (R2 = 0.975) was found between the volumetric flow rate (m3 s-1) and the power required to aerate the compost pile (W per 100 kg of swine mortality). Keywords: Airflow, Darcy’s law, Livestock, Modeling, Permeability, Pressure drop.

Cultivation Trial of an Edible and Medicinal Mushroom Species, Pleurotus Tuber-regium (Rumph. ex Fr.) Singer 1951 (strain 190212) on Various Lignocellulosic Substrates

In Central Africa, mushrooms are critically important non-timber forest products (NTFPs), both nutritionally and economically. A strain of edible and medicinal lignicolous fungus, Pleurotus tuber-regium (Rumph. ex Fr.) Singer 1951 (strain 190212), isolated from tissue (sclerotia), on PDA medium, was tested on corn grain and sawdust seedling substrates and on palm oil male inflorescence (Elaeis guineensis Jacq.), ground corn (Zea mays L) stalks and grass (Paspalum notatum L) soaked for 24 hrs then drained for 24 hours, and unsoaked ground corn (Zea mays L) stalks. The highest mycelial growth rate recorded was about 0.9 cm on the PDA medium; 5.97 cm on the corn-based seedling medium and 11.95 cm on the sawdust-based seedling medium. Total mycelial invasion on the PDA medium was observed on day 10, day 14 on the corn-based seedling medium, and day 24 on the sawdust-based seedling medium. The onset of mycelial invasion was noticeable on day 3 of seeding for all treatments T0 (control), T1 (Final substrate based on soaked ground corn stalks), T2 (Final substrate based on unsoaked ground corn stalks), and T3 (Final substrate based on turf). Total invasion of mycelium was obtained at day 15 of incubation for treatments T1 and T2, at day 18 for treatment T3 and at day 24 for treatment T0. The results obtained on treatments T1 and T2 respectively (14.95±3.12% and 15.65±1.06%) of the maize stalk substrate, lead us to believe that the strain 190212 of Pleurotus tuber-regium species used has adapted and requires an improvement of the medium with nitrogen-rich additives such as soybean meal. This could achieve the theoretical yield of 20% or more, according to which a substrate can be considered better in producing sporophores.

Testing the plastic-wrapped composting system to dispose of swine mortalities during an animal disease outbreak.

Composting has been used to dispose of animal mortalities and infected materials, such as manure and feed, during major animal disease outbreaks. In this study, we adapted the plastic-wrapped mortality composting system developed by the Canadian Food Inspection Agency during the 2004 highly pathogenic avian influenza outbreak to compost swine mortalities. The goals of the study were to evaluate the performance of the plastic-wrapped composting system to dispose of swine mortalities and to field test its ability to eliminate the spread of airborne pathogens through the aeration ducts. Two cover materials, ground cornstalks and woodchips, were tested using passively and actively aerated composting sheds. The mortalities were inoculated with Salmonella spp. and vaccine strains of Bovine herpesvirus-1 and Bovine viral diarrhea virus. Air samples collected from the upper aeration duct (air outlet) during the first 10 d of composting were negative for Salmonella and the viruses tested, which indicated that aerosol transmission of the pathogens was limited. The aeration plenum placed under the mortalities helped to keep conditions aerobic, as O2 concentrations of both passively and actively aerated test units were above 11%. Actively aerated cornstalks had the highest degree-hours (1,462 °C h d-1 ), which was followed by passively aerated cornstalks (1,312 °C h d-1 ), actively aerated woodchips (1,303 °C h d-1 ), and passively aerated woodchips (1,062 °C h d-1 ). After a 7-wk composting period, all three pathogens were inactivated based on quantitative polymerase chain reaction test results. The mortalities were not inoculated with the African swine fever virus, but temperature data showed that if they were, the system had the potential to eliminate this virus.

RESEARCH THE CELLULOSE PRODUCTION PROCESS FROM AGRICULTURAL WASTE

The problem of raw material supply of cellulose and paper production exists because of the shortage of wood resources. Nowadays the use of waste processing agricultural and technical plants is relevant for pulping. Corn, the production of whichUkraineis the fifth largest in the world, is one of the most common agricultural plants. Corn stalks are valuable cellulosic raw materials that can be used for the fibrous semi-finished products production for various purposes.The purpose of the research is to study the quantitative and qualitative characteristics of the pulping process from corn stalks in the per-acetic acid solution with various concentrations. The dry ground corn stalks without leaves used for research. This raw material contains 41.6 % cellulose, 17.95 % lignin, 12.1 % pentosans, 3.52 % resins, fats and waxes, 23.7 % substances that extracted with a 1 % alkali solution, 11.8 % substances that extracted with water and 7.9 % minerals. Pulping was carried out in laboratory conditions during 2, 3 and 4 hours by per-acetic acid solution with concentration 5.6; 7.7 and 9.8 % at a temperature 90 ºC and a water ratio of 7 : 1. The fibrous semi-finished products were obtained with a yield of 65.5‑22.1 % by weight of absolutely dry raw materials, a residual lignin content of 17.7‑3.2 %, and an ash content of 5.3‑3 %.Adequate second-degree regression dependencies for qualitative indicators of cellulose – yield, residual lignin content, and ash content from pulping conditions – are built based on the full factorial experimental design. The tasks of multi-criteria optimization are solved using Harrington’s desirability function in deterministic conditions and based on the Bellman-Zade optimality principle under partial uncertainty. Under determinism, the optimal pulping conditions are the concentration of per-acetic acid in the solution – 9.2 %, the duration of cooking – 2 hours and 20 minutes. Under partial uncertainty, the optimal conditions for pulping are the concentration of per-acetic acid in the solution – 9.1 % and the duration of cooking – 2 hours.

Effects of feeding high-moisture corn stover to gestating and lactating beef cows as an alternative to hay and corn silage on performance and reproduction

ABSTRACT The objectives of this study were to evaluate ensiled high-moisture corn stover as an alternative forage for beef cows. In Exp. 1, multiparous, gestating Simmental and Angus × Simmental cows (n = 96) were limit fed 1 of 3 treatments: (1) 60% high-moisture corn stover, 25% ground cornstalks, and 15% corn gluten feed (HMCS); (2) 60% corn silage, 25% ground cornstalks, and 15% corn gluten feed (SIL); or (3) 60% hay, 25% ground cornstalks, and 15% corn gluten feed (HY) from 108 ± 14 to 38 ± 14 d prepartum. In Exp. 2, lactating Simmental and Simmental × Angus cows (n = 79) were limit fed 1 of 2 treatments at calving: (1) 75% high-moisture corn stover and 25% dried distillers grains (HMCS2) or (2) 70% corn silage and 30% dried distillers grains (SIL2). Diets were limit fed to achieve NASEM (2016) requirements for maintenance and lactation. In Exp. 1, BW gain was greater (P

Do alternative litter Materials Affect performance, Welfare and Immune Response of Broiler Chicks?

Two hundred, one-day-old Cobb broilers were utilized as a part of this analysis. Chicks were examined and weighed on the entry day then, arbitrarily appointed to five litter treatments (20 birds per pen) with two duplicates for every treatment. The litter treatment consists of five different litter types: Wood shavings (WS), Ground rice straw, Ground rice straw + sand, Ground corn stalks straw, and Rice hulls. Behavioral perception was done twice per day, two days a week for six sequential weeks. Body weight (BW) and Feed intake rate per pen were measured each week, from which body weight gain (BWG) and feed conversion ratio (FCR) were calculated. At 42 days of age, welfare indices were measured including fear, stress, fluctuating asymmetry, plumage score, leg health and abnormalities. In addition, some carcass traits, litter quality were surveyed. Immune response against Newcastle diseased virus was determined at 21 and 29 days of age. Mortalities were recorded for every treatment. Our data cleared that birds reared on various litter components exhibited non-significant changes in feeding, drinking, standing, preening and scratching behaviors. While, birds reared on Rice hulls exhibited a significantly higher walking behavior and significantly lowered sitting and dust bathing behaviors. Bedding types had no obvious effect over BW, BWG, FCR and mortality percentages. Welfare indices were not affected by the type of litter substances. The type of the litter did not affect moisture content and compactness score of litter. In contrary, cleanliness score of the litter was worst in Ground rice straw compared to wood shavings. In addition, immune response against Newcastle diseased viruses not affected with types of litter. It concluded that, bedding types affect behaviors of broiler chicks. Ground rice straw, Ground rice straw + sand, Rice hulls and Ground corn stalks straw could be used as alternative bedding materials to wood shavings without affect on birds performance, welfare, health and immune response.

Influence of prepartum dietary energy on beef cow performance and calf growth and carcass characteristics

Objectives were to evaluate the effects of prepartum dietary energy intake on cow performance as well as performance and carcass characteristics of subsequent progeny. Spring-calving, mature cows (n=106 total) were blocked by BW and allotted to 1 of 2 treatments: ground hay and dried distillers grains plus solubles (REQ: TDN=61.8%, CP=11.0%, fat=2.1%), or corn bran and ground cornstalks (HE: TDN=70.3%, CP=10.0%, fat=5.7%). Treatments were limit-fed as isonitrogenous rations with REQ and HE providing 100% and 125% of TDN requirements, respectively, and were fed from 83±10d prepartum to calving. All cows were fed a common diet postpartum. Cow BW and BCS were recorded at the beginning of the feeding period, 24h post-calving, and at breeding. Milk production was estimated via the weigh–suckle–weigh technique 65±9 and 120±9d postpartum. Calf BW was measured at birth and at weaning (120±9d of age). Calves (n=86) were fed a common feedlot diet beginning 2d after weaning, and individual feed intake was monitored using GrowSafe. Progeny were slaughtered in 3 groups at an average 12th rib fat thickness of 1.3cm. From initiation of experiment to breeding, cow BW change was greater (P<0.01) and BCS change tended to be greater (P=0.09) for HE relative to REQ cows. Birth BW was greater (P=0.02) for calves born to cows fed HE with no increase (P=0.30) in percentage of unassisted births. There were no effects (P≥0.27) of treatment on calving date, milk production, or subsequent pregnancy rate. Calf weaning BW, initial feedlot BW, final BW, and days on feed were not affected (P≥0.20) by treatment. Feedlot DMI, ADG, and G:F were not different (P≥0.35). There was no effect (P≥0.27) of treatment on progeny morbidity. Although progeny born to HE dams tended (P=0.10) to have greater marbling scores at weaning, there was no effect (P≥0.60) of treatment on carcass marbling score or other carcass traits. Feeding cows 125% of TDN requirement during late gestation increased cow BW change and progeny birth body weight. Feeding cows 125% of TDN requirement during late gestation had no effect on pregnancy rate or progeny performance.

Influence of late gestation drylot rations differing in protein degradability and fat content on beef cow and subsequent calf performance.

Spring-calving, mature cows ( = 191 total) and their progeny were used to evaluate the effects of late gestation drylot rations differing in RUP and fat content on cow performance as well as performance and carcass characteristics of subsequent progeny. Cows were blocked by BW and anticipated calving date and assigned to 16 pens. Pens were randomly allotted to 1 of 2 treatments: limit-fed corn coproducts and ground cornstalks (COP; TDN = 64.4%, CP = 11.1%, RDP = 60.2% of CP, and fat = 5.1%) or limit-fed ground mixed, cool-season grass hay (HY; TDN = 55.7%, CP = 9.5%, RDP = 86.0% of CP, and fat = 2.3%). Treatments were limit fed as isocaloric, isonitrogenous rations from 88 ± 11 d prepartum to calving. All cows were fed a common diet postpartum. Cow BW and BCS were collected at the beginning of the feeding period, within 48 h after calving, and at breeding. Calf BW was collected at birth and at 64 ± 11 and 124 ± 11 d of age. Milk production was determined using the weigh-suckle-weigh technique at 64 ± 11 and 124 ± 11 d postpartum. At 124 ± 11 d of age, steers ( = 68) and nonreplacement heifer calves ( = 25) were weaned and placed on a common feedlot diet with individual feed intake monitored using GrowSafe. Feedlot calves were slaughtered at a commercial facility 35 ± 10 d after a minimum ultrasound 12-rib fat thickness estimation of 0.9 cm. After calving, cow BW was greater ( < 0.01) and BCS was greater ( < 0.01) for cows fed COP than for cows fed HY. Calf birth BW was greater ( = 0.04) for those born to cows fed COP with no difference ( = 0.43) in percentage of unassisted births across treatment. Cows fed HY were lighter ( < 0.01) at breeding with lower BCS ( = 0.03); nevertheless, overall pregnancy rate was not different ( = 0.80). No differences ( ≥ 0.22) in milk production were detected. For feedlot progeny, initial feedlot BW, final BW, and days on feed were not different ( ≥ 0.23), and as a result, no difference ( = 0.21) in feedlot ADG was detected. Feedlot DMI and G:F were not different ( ≥ 0.19) across treatments. Feedlot calf health was monitored with no differences ( ≥ 0.68) in morbidity and mortality observed. No differences ( ≥ 0.27) were detected for HCW, LM area, backfat, marbling score, yield grade, or KPH. Increased dietary RUP and fat content during late gestation increased cow BW and BCS but did not alter milk production, subsequent reproduction, or subsequent calf performance or carcass characteristics.

Performance of a plastic-wrapped composting system for biosecure emergency disposal of disease-related swine mortalities

A passively-ventilated plastic-wrapped composting system initially developed for biosecure disposal of poultry mortalities caused by avian influenza was adapted and tested to assess its potential as an emergency disposal option for disease-related swine mortalities. Fresh air was supplied through perforated plastic tubing routed through the base of the compost pile. The combined air inlet and top vent area is ⩽∼1% of the gas exchange surface of a conventional uncovered windrow. Parameters evaluated included: (1) spatial and temporal variations in matrix moisture content (m.c.), leachate production, and matrix O2 concentrations; (2) extent of soft tissue decomposition; and (3) internal temperature and the success rate in achieving USEPA time/temperature (T) criteria for pathogen reduction. Six envelope materials (wood shavings, corn silage, ground cornstalks, ground oat straw, ground soybean straw, or ground alfalfa hay) and two initial m.c.’s (15–30% w.b. for materials stored indoors, and 45–65% w.b. to simulate materials exposed to precipitation) were tested to determine their effect on performance parameters (1–3). Results of triple-replicated field trials showed that the composting system did not accumulate moisture despite the 150kg carcass water load (65% of 225kg total carcass mass) released during decomposition. Mean compost m.c. in the carcass layer declined by ∼7 percentage points during 8-week trials, and a leachate accumulation was rare. Matrix O2 concentrations for all materials other than silage were ⩾10% using the equivalent of 2m inlet/vent spacing. In silage O2 dropped below 5% in some cases even when 0.5m inlet/vent spacing was used. Eight week soft tissue decomposition ranged from 87% in cornstalks to 72% in silage. Success rates for achievement of USEPA Class B time/temperature criteria ranged from 91% for silage to 33–57% for other materials. Companion laboratory biodegradation studies suggest that Class B success rates can be improved by slightly increasing envelope material m.c. Moistening initially dry (15% m.c.) envelope materials to 35% m.c. nearly doubled their heat production potential, boosting it to levels ⩾silage. The ‘contradictory’ silage test results showing high temperatures paired with slow soft tissue degradation are likely due to this material’s high density, low gas permeability and low water vapor loss. While slow decomposition typically suggests low microbial activity and heat production, it does not rule out high internal temperatures if the heat produced is conserved. Occasional short-term odor releases during the first 2weeks of composting were associated with top-to-bottom gas flow which is contrary to the typical bottom-to-top flow typically observed in conventional compost piles. In cases where biosecurity concerns are paramount, results of this study show the plastic-wrapped passively-ventilated composting method to have good potential for above-ground swine mortality disposal.

POSSIBILITY OF USING SOME AGRICULTURAL RESIDUALS IN TOMATO NURSERY PRODUCTION

The main objective of this study is possibility of using some agricultural residuals as plant media to tomato nursery. These residues as ground cotton stalks, ground rice straw and ground corn stalks. Each residual contains different ratio of sand. Also, one sample was 75% peatmoss plus 25% velrmiculite as a control. Laboratory experiments were conducted to quantify real density (g/cm3), bulk density (g/cm3), hydraulic conductivity (cm/min), total porosity (%), and available water (g/g) as affected by different mixtures experimental. The tomato nursery was planted into trays in greenhouse to study some growth parameters as germination ratio, nursery high, plant weight, and leaves number as affected by different mixtures. The results show that in the media of (sand + ground cotton stalks), (sand + ground rice straw), and (sand + ground corn stalks) decreased sand ratio gave an increased in both total porosity and available water, the highest value of total porosity and available water were at mixture of (20% sand + 80%residuals). Also, the highest growth parameter of nursery as nursery weight and nursery high was obtained with the same mixture.

Effect of envelope material on biosecurity during emergency bovine mortality composting

The biosecurity of composting as an emergency disposal method for cattle mortalities caused by disease was evaluated by conducting full-scale field trials begun during three different seasons and using three different envelope materials. Process biosecurity was significantly affected by the envelope material used to construct the composting matrix. Internal temperatures met USEPA Class A time/temperature criteria for pathogen reduction in 89%, 67%, and 22%, respectively of seasonal test units constructed with corn silage, straw/manure, or ground cornstalks. In trials begun in the winter, survival times of vaccine strains of avian encephalomyelitis and Newcastle disease virus were noticeably shorter in silage test units than in the other two materials, but during summer/spring trials survival times in ground cornstalk and straw/manure test units were similar to those in test units constructed with silage.

GGE Biplot as a Novel Tool for the Investigation of Marigold (Tagetes erecta L.) Seedling Growth on Composted Corn Stalk as a Substrate

This project investigated the feasibility of using ground corn stalks as the substrate to cultivate marigold (Tagetes erecta L.). Five treatments including peat moss, composted corn stalks and freshly ground corn stalks were tested for their effects on marigold seedling growth. Seedling quality was described by several morphological and physiological parameters. Data were analyzed using analysis of variance and GGE biplot analysis. There were significant differences among the treatments for several growth parameters, such as seedling biomass, root biomass, stem diameter, leaf area, seedling vigor, chlorophyll content, photosynthetic rate, root activity, stomatal conductance, and intercellular CO2 concentration. Treatment T3, which contained composted ground corn stalks, had the best effect on marigold seedling growth. The results showed that corn stalk was a good substrate for marigold seedlings. GGE biplot demonstrated the substrate effects on marigold seedling quality, and graphically displayed the interrelationships among morphological and physiological parameters. T3 treatment was the best because four morphological parameters, including seedling biomass, roots biomass, stem diameter and seedling vigor, along with six physiological parameters fall into this sector. These results were consistent with the results analyzed by Statistical Analysis Software. For morphological parameters, the correlations are complicated. For physiological parameters, they were all positively correlated between each of two parameters.

Limit feeding nonlactating, nonpregnant beef cows with bunkered wet distillers grains plus solubles or distillers solubles

ABSTRACT Nonlactating, nonpregnant beef cows (593 ± 10.0 kg) were used in a completely randomized design to evaluate the performance of limit-fed diets containing bunkered wet distillers grains plus solubles (WDGS; n = 24) or bunkered condensed corn distillers solubles (DS; n = 22) compared with a control diet offered ad libitum (CON; n = 24). Cows were stratified by age and BW and randomly assigned to pens (3 pens/treatment, 7 or 8 cows per pen). The WDGS and DS were mixed and stored with 30% and 59% ground cornstalks (DM basis), respectively, for 30 d before feeding. Diets were fed for 76 d and formulated to maintain BW. Both WDGS and DS diets contained 41% by-product and 59% cornstalks at time of feeding, with DMI limited to 7.7 kg/d. The CON diet consisted of 43% bromegrass hay, 34% cornstalks, and 23% alfalfa haylage and was fed ad libitum (DMI = 10.4 kg/d). The WDGS diet was 4.1% fat and 0.24% sulfur. The DS diet was 5.5% fat and 0.37% sulfur on a DM basis. Initial BW and BCS among treatments were similar. Final BW was greater (P

Influences of Corn Co-products in Limit-Fed Rations on Cow Performance, Lactation, Nutrient Output, and Subsequent Reproduction

<h2>ABSTRACT</h2> Two experiments were conducted to evaluate the effects of corn gluten feed (CGF) or dry distillers grains with solubles (DDGS) in limit-fed diets on cow performance, lactation, nutrient output, and reproduction. Cows were maintained in concrete lots with open-front sheds and fence-line bunks. In Exp. 1, Simmental cows (n = 100) were blocked by age and calving date and assigned to 12 pens. Cows were fed 4.5 kg/d of alfalfa hay and isocaloric amounts of CGF (5.9 kg/d) or DDGS (5.55 kg/d) to meet requirements. The cows fed DDGS lost 16 kg less (<i>P</i> = 0.008) BW and had 0.9 kg/d less (<i>P</i> = 0.004) milk production, which resulted in a trend (<i>P</i> = 0.06) for slower calf ADG than for cows fed CGF. There was no difference in manure N (<i>P</i> = 0.13), but cows fed CGF did have greater (<i>P</i> = 0.04) manure P than cows fed DDGS. In Exp. 2, Simmental cows (n = 114) were blocked by age and calving date and assigned to 12 pens. Cows were fed 2.3 kg/d of ground cornstalks and isocaloric amounts of CGF (7.7 kg/d) or DDGS (7.2 kg/d) to meet requirements. In contrast to Exp. 1, the DDGS cows tended (<i>P</i> = 0.07) to lose more weight than those fed CGF. In addition, no differences were detected in milk production (<i>P</i> = 0.20) or calf ADG (<i>P</i> = 0.57). In both experiments, no differences were detected in reproductive performance. Corn co-products can be included up to 75% of a limit-fed diet. The higher fat content of DDGS compared with CGF did not improve reproduction.

Degradation of atrazine in soil by Streptomyces

Streptomyces sp. PS1/5 was able to degrade atrazine in soil while growing on a mixture of chitin and ground cornstalks as carbon and nitrogen source. The addition of triple superphosphate greatly stimulated the degradation of atrazine by Streptomyces sp. PS1/5, while the addition of lime stimulated the degradation to a lesser degree. Ferrous sulfate had a small positive effect on atrazine degradation. Atrazine in soil was reduced from 20 g g‘1 dry soil (20 ppm) to 6 ppm within 30 days in soil amended with 8% chitin, 2% cornstalks and 0.1% triple superphosphate and incubated at 25°C. The results indicate that it may be possible to use bacteria of the genus Streptomyces to degrade pesticide residues in contaminated soils.

Xylanase Activity of Phanerochaete chrysosporium

Xylan-degrading enzymes were induced when Phanerochaete chrysosporium was grown at 30 degrees C in shake flask media containing xylan, Avicel PH 102, or ground corn stalks. The highest xylanase activity was produced in the corn stalk medium, while the xylan-based fermentation resulted in the lowest induction. Analytical and preparative isoelectric focusing were used to characterize xylanase multienzyme components. Preparative focusing was performed only with the cultures grown on Avicel and corn stalk. Of over 30 protein bands separated by analytical focusing from the Avicel and corn stalk media, three main groups (I, II, and III) of about five isoenzymes each showed xylanase activity when a zymogram technique with a xylan overlay was used. Enzyme assays revealed the presence of 1,4-beta-endoxylanase and arabinofuranosidase activities in all three isoenzyme groups separated by preparative isoelectric focusing. beta-Xylosidase activity appeared in the first peak and also as an independent peak between peaks II and III. Denatured molecular masses for the three isoenzyme groups were found to be between 18 and 90 kDa, and pI values were in the range of 4.2 to 6.0. beta-Xylosidase has an apparent molecular mass of 20, 30, and 90 kDa (peak I) and 18 and 45 kDa (independent peak), indicating a trimer and dimer structure, respectively, with pI values of 4.2 and 5.78, respectively. Three more minor xylanase groups were produced on corn stalk medium: a double peak in the acidic range (pI 6.25 to 6.65 and 6.65 to 7.12) and two minor peaks in the alkaline range (pI 8.09 to 8.29 and 9.28 to 9.48, respectively). The profile of xylanases separated by isoelectric focusing (zymogram) of culture filtrate from cells grown on corn stalk media was more complex than that of culture supernatants from cells grown on cellulose. The pH optima of the three major xylanase groups are in the range of pH 4 to 5.5.

Production of Bacterial and Yeast Biomass in Ground Corn Cob and Ground Corn Stalk Media

The production of biomass using ground corn cobs and ground corn stalks and a 1:1 (w/w) mixture of the two was studied using Cellulomonas uda in a monoculture and in mixture with Candida utilis. The addition of C. utilis improved the amino acid content of the biomass. With the combination of C. uda and C. utilis, there was more soluble protein in the growth medium. With the addition of C. utilis to the corn cob fermentation, the relative nutritive value increased from 45.7% with a monoculture to 72.6% with a mixed culture. The crude protein also increased from 13.5 g/100 g to 21.1 g/100 g. The ratio of enzyme activity with carboxymethyl cellulose to that of filter paper was about two at the 5th day of fermentation.

Decomposition in soil of specifically 14C-labeled model and cornstalk lignins and coniferyl alcohol over two years as influenced by drying, rewetting, and additions of an available C substrate

Losses of 2-side chain and ring-carbons of coniferyl alcohol units in model and cornstalk lignins were about 22, 33 and 40% after 6, 12 and 24 months incubation in a neutral sandy loam top soil. Comparable values for the O 14CH 3 carbons were 46, 66 and 69%, respectively. The free coniferyl alcohols decomposed more rapidly during the first 6–9 months and C loss values for the ring- and 2-side chain carbons were about 47% at 6 months and 58% at 2 yr. Loss of the OCH 3 C was about 61% at 6 months and 72% at 2 yr. The addition of ground cornstalks at 0, 6, 12 and 18 months did not influence the total amount of 14C evolved from any of the treatments. During the first week after the fresh cornstalk additions at 6 months the amount of 14C evolved was increased from about 0.3% to 0.8% of the applied activity. After 1 month, however, losses from the controls were the same as for the supplemental treatments.

The Significance of the Rate of Organic Matter Decomposition on the Aggregation of Soil

AbstractLaboratory studies of different types and amounts of organic materials added to a moist soil resulted in maximum release of CO2 after about 48 hours and in maximum stability of soil aggregates after about 2 weeks incubation. The experiments indicated that a fairly rapid and sustained rate of decomposition of organic residues is a necessity in the stabilization of soil aggregates. Corn stover was more effective than corn cobs—when ground to similar fineness. The benzene‐alcohol and the alkali soluble extracts from a soil that had been incubated with ground corn stalks greatly increased the aggregate stability when added to an otherwise untreated soil. The benzenealcohol soluble fraction likely reduced the rate of wetting of soil aggregates. As a consequence the dispersion effect of water was less pronounced. Water‐soluble extracts had little influence on stabilizing soil aggregates.