Rice Straw Substrate Research Articles

Yield Of Edible Pleurotus Mushrooms Grown On Rice Straw With And Without Chicken Manure Supplementation In Morogoro, Tanzania

An experiment was conducted to determine the performance of different species of edible Pleurotus mushrooms grown on rice straw substrate with and without chicken manure supplementation. The Pleurotus species /varieties tested were P. flabellatus of Tanzania, India and Thailand origin, and P. sajor caju from Tanzania. Rice straw with and without chicken manure were used as substrates. The results showed that the duration of time from spawning to pin formation and from pin formation to first harvest was not significantly different for both treatments (p=0.05). The yields of the Indian and Thai P. flabellatus varieties were significantly higher than yields of P. flabellatus and P. sajor caju from Tanzania (p=0.05). The yields of the substrate amended with manure and un-amended were not significantly different. These results suggest that yields of the studied varieties of Pleurotus mushrooms are not influenced by substrate amendments rather other factors like spawn quality. This implies that use of high quality spawn can be a good determinant of high yields. On the other hand local varieties had lower yields than exotic varieties under the same treatments showing that research and breeding to screen and select for good quality local edible varieties can adequately improve yields and utilization of local breeds/varieties. Keywords : Pleurotus flabellatus - Pleuotus sajor caju – yield – amendmended, un-amended substrates Tanzania Journal of Forestry and Nature Conservation Vol. 77 2008: pp. 46-53

The Effect of Pleurotus spp. Fungi on Chemical Composition and in vitro Digestibility of Rice Straw

This study was carried out to test the potentially of using rice straw substrate for the cultivation of four Pleurotus species including Pleurotus florida, Pleurotus djamor, Pleurotus sajor-caju and Pleurotus ostreatus and the effect of these species on the chemical composition, cell wall degradation and digestibility of rice straw. Rice straw soaked in water for 24 h and then it was pasteurized at 100 degrees C for 6 h. Rice straw was inoculated with spawns of four Pleurotus fungi (Pleurotus florida, Pleurotus djamor, Pleurotus sajor-caju and Pleurotus ostreatus) and packed in the plastic bags and incubated in a fermentation chamber at 23-27 degrees C and 75-85% relative humidity. After 60th day, rice straw samples from all groups were taken and analyzed for chemical composition and in vitro digestibility. The data obtained were analyzed according to the complete randomized design model consisting of four treatments plus one control and four replicates. The results of this study showed that fungal treatment increased (p<0.05) the Crude Protein (CP), silica, Ca and P contents of the rice straw but the hemicellulose, Organic Matter (OM), Acid Detergent Fiber (ADF), Neutral Detergent Fiber (NDF) and Acid Detergent Lignin (ADL) contents decreased. However, the ability of the fungi to degrade these components varied among the species. The ability of Pleurotus sajor-caju and Pleurotus ostreatus were higher than the other species in decreasing the hemicellulose, NDF, ADF and ADL contents. The highest Biological Efficiency (BE) was produced by sajor-caju species with 56.02 and the lowest was belong to Pleurotus djamor species with an average 51.17%. All species of fungi incubated on rice straw showed increased (p<0.05) the in vitro dry mater and organic matter digestibility. Rice straw treated with sajor-caju fungus had the highest in vitro dry matter digestibility (IVDMD) and in vitro organic matter digestibility (IVOMD) with 80.10 and 82.18%, respectively. In general this experiment cleared that treatment with sajor-caju can improve the quality of rice straw to be useful feed for ruminant nutrition.

Effects of supplementing rice straw growth substrate with cotton seeds on the analytical characteristics of the mushroom, Pleurotus florida (Block & Tsao)

Incorporation of cotton seed powder (3%) with rice straw substrate, while culturing Pleurotus florida, enhanced mushroom yield and net protein yield. The free sugars and polymeric carbohydrates were 13.2% and 39.6% in mushrooms grown on rice straw (RS-M) and 8.3% and 19.8% in the mushrooms grown on cotton seed-supplemented rice straw (CS-M). There was a significant decrease in the total dietary fibre content due to cotton seed supplementation. There was a desired softening (∼45% reduction in firmness) observed in the CS-M as measured on a Zenken texturometer. The free amino acids showed about 125% increase in the CS-M compared to the RS-M. There was a significant increase in most of the essential amino acids, such as leucine, isoleucine, valine, cysteine, methionine and phenylalanine. The total protein content (Kjeldahl N × 4.38) showed ∼90% increase in the CS-M. The total lipids increased by 35% due to cotton seed supplementation of the rice straw substrate; there was a predominance of unsaturated fatty acids, and linoleic acid in particular.

Evaluation of Pleurotus ostreatus and Pleurotus sajor-caju nutritional characteristics when cultivated in different lignocellulosic wastes

Fungi of Pleurotus genus present a high content of proteins and vitamins and low content of fat. Based on these facts, this work aimed to evaluate some nutritional characteristics of fruiting bodies of Pleurotus ostreatus and Pleurotus sajor-caju after the first harvest, using rice straw and banana straw as substrates. Both species presented a higher content of ash in the rice straw substrate (5.86% average) than in the banana straw (5.36%). P. sajor-caju CCB 019 showed higher moisture and fibre content when cultivated in rice straw (88.08% and 9.60%, respectively) than in banana straw (83.17% and 7.60%, respectively). The other parameters were not influenced by the cultivation substrate. The protein content (from 1.54% to 3.10%) of Pleurotus fresh fruiting bodies proved to be similar to, or even higher than, the values observed in various vegetables but lower than the protein contents of eggs, meat and cheese.

Enhancement of bioconversion efficiency and chemistry of the mushroom, Pleurotus sajor-caju (Berk and Br.) Sacc. produced on spent rice straw substrate, supplemented with oil seed cakes

Abstract The effect of supplementing the spent rice straw substrate, selected at two different levels of bioconversion efficiency (BCE), 8 and 12%, of Pleurotus sajor-caju, with extra organic nitrogen (in the form of oil seed cakes) was studied on further production of mushrooms, their chemistry and the increase in the in vitro dry matter digestibility (IVDMD) of rice straw. The spent rice straw was supplemented with the oil seed cake powders in amounts equivalent to 0.15–0.60% of nitrogen present in the undegraded rice straw, that is used for mushroom culturing. The cotton seed powder proved to be better in enhancing the mushroom yields (up to 12 times those of the unsupplemented spent straw), than the other oil seed cakes such as mustard, niger, soyabean and sunflower. Chemically, the cottonseed powder supplemented mushrooms showed increased protein, fat and decreased carbohydrate contents. Also, there was a significant reduction in the spawnrun period, compared to the unsupplemented rice straw. A considerable increase in the IVDMD of the supplemented spent straw was observed as compared to the IVDMD of the unsupplemented spent straw. Due to cotton seed cake supplementation, there was about a 27% increase in the IVDMD value of the spent straw that resulted in 8% BCE. The mushrooms produced on the spent rice straw substrate, with supplementation of cottonseed powder, did not contain any residues of gossypol, and accordingly, they can be a valuable food or feed.

Chemical and biochemical changes in the rice straw substrate related to the morphogenesis, cropping patternand yield of Pleurotus florida (Block & Tsao.)

SummaryGrowth and yield of Pleurotus florida on rice straw were studied as a function of temperature. At an ambient temperature of 20˚C, a maximum bioconversion efficiency (yield to substrate ratio, both on a dry-weight basis) of 14.5% was recorded. The net yield was observed over 2–3 flushes, with an interflush period of ca. 7.d. Increase in bioconversion efficiency (BCE) decreased left-over spent substrate and increased the loss of growth substrate as CO2 and H2O. An increased solubility of the growth substrate was observed with increase in BCE. In general, increase in sugars, amino acids, and decrease in phenols, cellulose, hemicellulose and lignin were observed; however amino acids decreased at high levels of BCE. Likewise, the decrease in lignin content was not important above a 10% increase in BCE. Flush co-ordinated operation of the degradatory enzymes in the rice straw substrate was studied. Whilst CMC-ase, b-glucosidase, hemicellulase and protease showed a continuous increase over all the flushes, laccase showed a decline only after the first flush, reflecting the possible non-requirement for lignin degradation thereafter. The growth of the fruiting primordium into a mature fruiting body took 72.h was characterized by an active increase in cellulase(s), hemicellulase(s) and, protease in particular. Laccase activity declined. This observation is associated with the requirement for carbohydrates and protein for growth and development of the fruiting bodies. Hexosamine content in the rice straw substrate increased until the end of spawnrun and declined thereafter, in accordance with the fructification.

Biodegradation of gossypol by the white oyster mushroom, Pleurotus florida, during culturing on rice straw growth substrate, supplemented with cottonseed powder

The capacity of the white oyster mushroom, Pleurotus florida to biodegrade gossypol was studied, when grown on rice straw supplemented with cottonseed powder. The mushroom fruiting bodies did not contain any residues of gossypol at concentrations of cottonseed powder ≡0.15–0.60% nitrogen contents of rice straw at the end of mycelial ramification. However, the cottonseed supplementation (at 0.30% N level itself) caused a doubling in the mushroom yield and its protein content, per unit weight straw substrate. The mushroom mycelium when grown on synthetic medium in liquid cultures was able to biodegrade gossypol. A pre-incubation period of 5 days before the addition of gossypol into the culture medium, an inoculum load ≡10 mg and an incubation period of 10 days at 25 °C caused the biodegradation of 100 μg gossypol. Increased concentrations of gossypol required increased duration and increased inoculum levels to effect biodegradation. However, the effect was more pronounced with an increase in inoculum density. The fungal monoculture when grown in rice straw (powder) (5%) + glucose (1%) liquid culture medium, showed an increase in hexosamine content and laccase activity that produced an increased degradation of gossypol over an incubation period from 5 to 25 days. Enzymic extracts of the mycelial monoculture raised on the chopped rice straw substrate when incubated with 100 μg of gossypol demonstrated its biodegradability; the increase in enzyme concentration showed enhanced gossypol degradation. This study adds to the world list of organic compounds that Pleurotus is able to biodegrade, and explains the cause of non-yellowing of the white oyster mushroom (P. florida) fruiting bodies, during culture on rice straw with supplementation of cottonseed powder for enhancing the mushroom yields.

Technique for preparation of anaerobic microbes: Rodshaped cellulolytic bacteria

Preparation of anaerobic-rod cellulolytic bacteria with coating technique has been conducted. Steps of the processes involved were cultivation, coatin g , evaporation, and drying. Coating agent used was Gum Arabic, and drying techniquesconducted were freeze drying and sun drying. pH of culture media was firstly optimized to obtain the maximal population ofbacteria. Both coated and uncoated preparates were subjected to drying. Morphological and Gram type identifications showed that uncoated preparate dried with freeze drying is not contaminated (ie. all bacteria are rod shape with Gram-negative type) while the one dried with sun drying is not morphologically pure (ie. containing of both rod and coccus shapes with Gram negative and positive). The coated preparates dried by both freeze and sun drying, were not contaminated (ie. all are rods with Gram-negative). The coating and drying processes decreased viability of preparates significantly. However, the decreasing of viability of coated preparate are lower than uncoated preparate (ie. 89 vs. 97%). Total count of bacteria in sun-drying coated preparate are higher (P<0.05) than the uncoated preparate (ie. 3.38 x 1010 vs. 1.97 x 1010 colony/g DM). Activity of sun-drying coated preparate to digest elephant grass and rice straw was higher (P<0.01) than the sun-drying uncoated preparate with the in vitro DMD values were 42.7 vs. 35.5% for elephant grass substrate and 29.3 vs. 24.6% for rice straw substrate. Therefore, it is concluded that coating technique has a positive effects on the preparation of rumen bacteria. Key words : Anaerobic bacteria, coating, drying

Effect of micromineral and phenylpropionic acid on performances of coccus and rod-shaped cellulolytic bacteria degrading fibre of forage

Performances of coccus and rod-shaped cellulolytic bacteria as inoculum for fermentation of fibrous substrate treated with growth or stimulator factors have been conducted by in vitro. The bacteria were firstly separated and purified based on their morphological shape and followed by identification of their gram type. The treatments as follow : control, Cu (1,0 ppm), Zn (6,0 ppm), Se (0,02 ppm), Fe (16 ppm), Co (0,02 ppm), Mn (4,0 ppm), Mo (0,002 ppm), and phenylpropionic acid (PPA) (30 ppm). These factors were added into fermentation media individually (F.P/S) and as mixture (Mix F.P/S). Substrates used were cellulose and rice straw. Measurements were bacterial digestion of drymatter (DMD), bacterial count, volatile fatty acids (VFA) and NH3-N contents. Gram test showed that inoculum cellulolytic cocci and rods are gram-positive and gram-negative consecutively. The results of treatments showed that Cu, Zn, Co, Mo and PPA improve digestibility of cellulose and rice straw substrates by cellulolytic cocci significantly (p<0.05), and beside Mn, these factors increased the total count of cellulolytic cocci in fermentation medium significantly (p<0.05). The growth or stimulator factors increasing digestibility values of the substrates by cellulolytic rods significantly (p<0.05) were Cu, Zn, Se, Fe, Co, Mn and Mo (except Mn for rice straw substrate). Only 4 elements of the growth and stimulator factors increasing the total count of cellulolytic rods during fermentation of cellulose and rice straw substrates significantly (p<0.05) that is Zn, Co, Mn and Mo. Digestibility of cellulose by cocci is higher than by rods (34.65% vs 29.87%), however, the digestibility of rice straw by both bacteria did not show difference. Digestibility of both cellulose and rice straw substrates was improved by cocci and rods combination and improved further when treated with Mix F.P/S. Parameters of fermentation media ecosystem measured (i.e. total count of bacteria, VFA and NH3-N) were generally changed to be better when treated with Mix F.P/S. It is concluded that performances of cocci and rods in digesting fibrous substrate are different, and growth or stimulator factors improved the activities of both group of bacteria significantly. Key words : Cellulolytic cocci, cellulolytic rods, growth and stimulator factors, bacterial digestion

Radiation and fermentation treatment of cellulosic wastes

The effect of radiation pasteurization of sugar cane bagasse and rice straw and fermentation using various strains of fungi were studied for upgrading of cellulosic wastes. The initial contamination by fungi and aerobic bacteria both in bagasse and straw was high. The doses of 30 kGy for sterilization and 8 kGy for elimination of fungi were required. Irradiation effect showed that rice straw contained comparatively radioresistant microorganisms. It was observed that all the fungi (Hericium erinacium, Pleurotus djamor, Ganoderma lucidum, Auricularia auricula, Lentinus sajor-caju, Coriolus versicolor, Polyporus arcularius, Coprinus cinereus) grow extending over the entire substrates during one month after inoculation in irradiated bagasse and rice straw with 3% rice bran and 65% moisture content incubated at 30°C. Initially, sugar cane bagasse and rice straw substrates contained 39.4% and 25.9% of cellulose, 22.9% and 26.9% of hemicellulose, and 19.6% and 13.9% of lignin + cutin, respectively. Neutral detergent fibre (NDF) values decreased significantly in sugar cane bagasse fermented byG. lucidum, A. auricula andP. arcularius, and in rice straw fermented by all the 8 strains of fungi. Acid detergent fibre (ADF) values also decreased in bagasse and rice straw fermented by all the fungi.P. arcularius, H. erinacium, G. lucidum andC. cinereus were found to be the most effective strains for delignification of sugar cane bagasse.

Improvement of the bioconversion and biotransformation efficiencies of the oyster mushroom ( Pleurotus sajor-caju) by supplementation of its rice straw substrate with oil seed cakes

Supplementing the rice straw substrate colonized by the mushroom, Pleurotus sajor-caju, with powdered oil seed cakes (mustard, niger, sunflower, cotton, and soyabean) increased the mushroom yields between 50 and 100%, compared to the unsupplemented substrate. Oil seed cake supplementation also effected an increase in the solubility of the rice straw substrate; there was an increase in the contents of free sugars and amino acids, and a decrease in cellulo-hemicellulosics. Correspondingly, there was also an increase in the activities of carboxymethylcellulase, hemicellulase, and protease. In vitro dry matter enzymatic digestibility measured by two-step enzymatic digestibility of the spent straw (material remaining from the straw substrate, supplemented with the oil seed cakes), indicated a significant increase over that of the spent straw derived from the unsupplemented lot.

Degradation of rice straw by Pleurotus flabellatus

AbstractDegradative changes in the constituents of rice straw substrate during the growth and commercial production of fruit bodies by Pleurotus flabellatus were investigated. There was a continuous increase in the free sugars from the time of inoculation until the end of harvesting of the fruit bodies, whereas the free amino acids reached a maximum at the end of mycelial growth and showed a slight decrease after fructification. Glucose, xylose, arabinose, cellobiose and a higher oligosaccharide represented the spectrum of sugars produced. Of the 12 amino acids (apart from two peptides) identified, aspartic acid, histidine and tyrosine were the major components. Solubilities and spectral characteristics of lignin degraded in the straw substrate were studied using alkali‐extracted lignin. Laccase and protease activities in the straw substrate at different stages of fungal degradation could be correlated to the decreases in the staw lignin and protein contents, respectively. Colour reactions of the fungus on several phenolic media, demonstration of phenolic oxidases in the straw substrate, and ability of the fungus to degrade lignin conclusively proved that the fungus under study is a typical ‘white rot’ fungus. Degradation of the straw substrate by the fungus reached a maximum at the end of harvest of the fruit bodies. The spent straw substrate (left over after harvesting the fruit bodies) contained free sugars and amino acids, respectively 5 and 2 times the concentration of those in the undegraded straw substrate, and lignin decreased to about 25% of the level in the straw before fermentation. Potential applications of the spent straw substrate as an upgraded form of rumen feed and for the production of single‐cell protein are discussed.

Microbial biomass production from rice straw by fermentation with Penicillium janthinellum

Production of microbial biomass through fermentation of pretreated rice straw using Penicillium janthinellum (St-F-3B) is reported, with emphasis on the use of non-effluent generating pretreatment procedures. The fungus readily metabolized a rice straw substrate that had been subjected to alkali pretreatment by steaming at atmospheric pressure followed by the neutralization of the alkali. The crude protein content of the microbial biomass averaged 15–20%. The fermentation could be carried out in aerated-agitated fermenters using fertilizer grade nutrient salts to produce a biomass with 17.5% crude protein. When operated on a semicontinuous basis using 20% of the previous batch as inoculum, successive batches produced a biomass product with 12–19% crude protein content in 48 h. The problems of developing a technology for protein from agricultural residues with particular reference to developing countries are discussed.

Microbial Fermentation of Rice Straw: Nutritive Composition and In Vitro Digestibility of the Fermentation Products

Rice straw was fermented with Cellulomonas sp. and Alcaligenes faecalis. Microbial cells and undigested residue, as well as chemically treated (NaOH or NH4OH) and untreated straws, were analyzed for nutrient composition and in vitro digestibility. In a typical fermentation, 75% of the rice straw substrate was digested, and 18.6% of the total substrate weight that disappeared was recovered as microbial protein. The microbial cell fraction was 37% protein and 5% crude fiber; the residue was 12% protein and 45% crude fiber. The microbial protein amino acid profile was similar to alfalfa, except for less cysteins. The microbial cells had more thiamine and less niacin than Torula yeast. In vitro digestibility of the microbial protein was 41.2 to 55%, that of cellulose was 52%.

Comparison of the Growth and Production of Carps in Polyculture Ponds with Supplemental Feed using Rice Straw and Kanchi as Substrates

An experiment was carried to compare the performance of rice straw and kanchi in carp polyculture ponds with supplemental feed. The experiment included two treatments in triplicates: a) rice straw substrate (3x625 kgha-1) with supplemental feeding and b) kanchi substrate (390 kanchi pond-1) with supplemental feeding. Fingerlings (n=40) of rohu, Labeo rohita (23.3±0.5 g), catla, Catla catla (26.0±0.6 g), mrigal, Cirrhinus mrigala (25.4±0.7 g), common carp, Cyprinus carpio (28.5±1.9 g) and silver carp, Hypophthalmychthys molitrix (32.1±1.3 g) were stocked at 3:2:2:2:1 ratio. Fish growth and weight gains did not vary between the rice straw and the kanchi treatment except in catla (P&gt;0.05). Daily and total weight gains of catla was 48 and 32% higher in the kanchi treatment than in the rice straw treatment (P&lt;0.05). However, the rice straw treatment gave more profit than the kanchi treatment. Based on fish production and gross margin, the rice straw treatment seems better for resource-poor farmers.DOI: 10.3126/on.v8i1.4316