Synthetic Compost Research Articles

Effect of formaldehyde exposure on phytochemical content and functional activity of Agaricus bisporus (Lge.) Sing.

In this study, the effect of formaldehyde on phytochemical content and antioxidant activity of Agaricus bisporus was investigated. Synthetic compost based on wheat straw was prepared by fermentation and disinfection. After steam pasteurization, 5 g of A. bisporus mycelia were inoculated into 1 kg of compost. To determine the effects of formaldehyde, 2, 4, and 6% concentrations were added to the composts, while compost without formaldehyde was used for the control group. The harvesting period was set at 10 weeks. Total phenolic and flavonoid content, macro- and microelement profile, and phenolic content were analyzed in the harvested A. bisporus samples. Macro- and microelement content was determined by ICP-OES, and phenolic compound profile was determined by LC-MS/MS analysis. Formaldehyde levels in A. bisporus samples were determined by the acetylacetone spectrophotometry method. The antioxidant capacity of A. bisporus samples was determined by DPPH scavenging activity; antimutagenic effects of samples were determined by Allium test. Application of 2, 4, and 6% formaldehyde resulted in a 1.12-, 1.19-, and 2.07-fold reduction in total phenolic content, respectively. The total phenolic content was reduced between 34.4% and 71.8%. These changes were confirmed by LC-MS/MS analysis. Compounds such as protocatechuic acid, salicylic acid, ferulic acid, and 4-OH benzoic acid, which were detected in the control group, could not be detected in the samples treated with 6% formaldehyde, and it was found that the application of formaldehyde reduced the phenolic content. Similar changes were also observed in macro- and microelements, and significant changes in elemental contents were observed after formaldehyde application. While the presence of formaldehyde at a low level, which may be due to natural production, was detected in the control group, a residue of 11.41 ± 0.93 mg/kg was determined in the 6% FMD applied group. All these changes resulted in a decrease in the antioxidant activity of A. bisporus. The DPPH scavenging activity, which was determined in the range of 21.6–73.3% in the control samples, decreased to 12.3–56.7% in the samples treated with formaldehyde. These results indicate that the application of formaldehyde at different stages of A. bisporus cultivation leads to significant changes in the nutritional value and biological activity of A. bisporus.

Studies on Different Cultural Parameters on Vegetative Growth of Straw Mushroom (Volvariella volvacea)

Volvariella volvacea is an edible straw mushroom of tropics and subtropics. The optimum temperature and moisture for the growth of this mushroom are 35°C and 57–60%, respectively. Mushrooms grow on natural or semi synthetic compost and absorb nutrients for their survival. The maintenance and revival of pure culture mycelium with magnificent quality is the first critical stage towards the success of spawn preparation. To maintain any microorganism in artificial conditions, the former has to be cultured on a suitable nutrient medium. All microbes require a set of conditions under which they can grow and sporulate best and culture medium is the major factor influencing fungal cultivation. Five different culture media both in liquid and solid phase, five different pH levels and five temperature regimes were evaluated for the vegetative growth of four different strains of Volvariella volvacea i.e. DMR-484, DMR-463, DMR-819 and DMR-820. Among five liquid media studied, malt extract was found to be the best medium for the growth of all the strains of V. volvacea both in solid as well as in liquid phase. Out of five different pH levels evaluated for the growth of V. volvacea pH7.0 was observed to be the best pH for the growth of all the strains of the test fungus. Out of five different temperature regimes evaluated, 30°C was observed to be the ideal temperature for the growth of V. volvacea.

Impacts on Productivity through Sustainable Fertilization of Nopal (Opuntia Ficus-Indica) Crops Using Organic Compost

This paper shows the results obtained when evaluating current practices in cultivation processes of nopal. Production of nopal in the borough of Milpa Alta in Mexico City has been based for more than 40 years on the use of high doses of fresh cow manure (up to 600 t ha-1). It is necessary to consider the effects that this type of fertilization could have on the environment. In order to compare the effect of different fertilization methods on the production, quality and shelf-life of cladodes, three-year-old cactus plants were fertilized with compost, compost leachate, fresh manure cow and synthetic fertilizer; plants treated with water served as a control. The plants fertilized with compost (leached or solid) tended to a higher yield (g) per plant, although there were no significant statistical differences between treatments. Cladodes produced with solid compost or fresh manure showed a lower pH (4.7) than those produced with water to the soil. Cladodes produced with synthetic fertilizers showed higher shear strength than those produced with manure. Cladodes produced with synthetic fertilizer and compost leachate took more days to show shelf darkening (oxidation) than those produced with soil water. In addition, the use of compost showed a significant impact on cost reduction during the production nopal given a lower cost against manure and synthetic fertilizer.

Yield of different white button strains in sugar cane by product-based composts

The production of quality compost for Agaricus bisporus using alternative and local agricultural wastes beyond the search for productive strains are among the main factors related to improve yield. Thus, we evaluated the effect of compost nitrogen supplementation type using two compost formulation based on sugar cane by-products such as straw and bagasse as raw materials: (1) classic compost using chicken manure and (2) synthetic compost using soybean bran, urea and ammonium sulfate, for the cultivation of the five strains of A. bisporus: ABI-05/03, ABI-04/02, ABI-06/05, and ABI-09/10 ABI-09/11. We found that the classic compost obtained average temperature and mass loss of 10.56 and 13.29% higher than the synthetic compost, respectively, during the composting, pasteurization and conditioning process. The classic compost achieved greater yield in the end of 25 days of harvest by the strains ABI-05/03, ABI-06/05 and ABI-04/02 corresponding to 26.78, 25.34 and 24.71%, respectively. We concluded that the classic and synthetic, based on sugar cane straw and bagasse are suitable agricultural waste for A. bisporus cultivation and the classic compost obtained higher composting temperatures in relation to synthetic compost, corroborating higher yields and more defined-pattern cultivation cycle for all strains when grown in classic compost. Key words: Agaricus bisporus, by-products, supplementation, classic, synthetic.

Nutritional value and amino acids composition of the mushroom (Agaricus bisporus) at different stages of its development

The study of the nutritional value and amino acid composition of the mushroom (<i>Agaricus bisporus</i>) was carried out with the Somycel 653 strain cultivated on a synthetic compost containing rye straw, broiler chicken manure and gypsum. In 4 developmental stages of the whole fruit-bodies and the caps and stipes the following were determined: dry matter, vitamin C, nitrates, total nitrogen, crude protein (N × 4.38) and amino acid composition. It was observed that in all stages of development the levels of total N and crude protein are significantly higher in the caps than in the stipes. From the amino acid composition it appears that the caps of stage 4 contain the highest amounts of essential and total amino acids as compared with caps, stipes and whole sporophores found in any developmental stage. This is correlated with the opening of the mushrooms in stage 4. It was observed that the nitrates level tends, to be higher in the cap than in the stipe.

Compost Physico-chemical Factors that Impact on Yield in Button Mushrooms,Agaricus bisporus(Lge) andAgaricus bitorquis(Quel)Saccardo

Button mushrooms, Agaricus sp. are secondary decomposers that require nutritious and very selective composts for their growth. Selectivity of these composts is influenced by both biological and physico-chemical characteristics of composting process. The conventional method of preparing button mushroom composts is to use a combination of horse manure, hay and a high nitrogenous source such as chicken manure. These materials are composted over time until the compost is 'mature'. In the absence of the materials above, several alternatives can be used. An experiment was designed to use locally available materials in making two synthetic composts of grass and maize stalk. The objective was to find out factors that contribute to making compost that give high yields of button mushrooms. Three strains of mushrooms A. bisporus, A. brunescence and A. bitorquis were planted in three different composts; horse manure was used as control, maize and grass as synthetic in a complete randomized design. Nitrogen content of each compost was calculated, moisture content and temperature of the compost were recorded throughout composting and during conditioning period. Yields of mushrooms were taken in three dif ferent flushes. Results of the mean yields of three mushroom strains grown indicated that the two composts were significantly dif ferent; the grass compost gave significantly superior yields of mushrooms of 549 gm/kg of compost compared to the conventional horse manure which gave 435.66 gm/ kg of compost. The maize straw synthetic type gave 327.33 gm/ kg of compost (pd0.05). Significantly very low yields were realized in the maize straw synthetic type. Though many factors contribute to the yield of mushrooms, the superiority of the grass synthetic compost may be attributed to three main factors: suf ficient nitrogen levels at spawning, a more open structure that facilitated aeration during composting as well as conditioning, and the high temperature regime maintained during composting. Maize straw synthetic compost on the other hand remained soggy due to the spongy stalks which imbibed water readily, especially during steam pasteurization. This resulted in the failure of a temperature build up. Temperature build -up in phase I as well as at peak heating. Moisture content during composting and aeration of the compost heap are significant factors in mushroom compost preparation.

Organic Pepper Production Systems Using Compost and Cover Crops

ABSTRACT In a national survey and through statewide focus groups, organic farmers identified pest management and soil fertility as their most critical vegetable research needs. In response, a long- term experiment was established to compare pepper (Capsicum annuum L.) growth, productivity, insect populations, harvest cullage and postharvest weight loss under conventional and organic management. Treatments from the first 3 years (1998 to 2000) consisted of combinations of two synthetic fertilizer and three compost-based certified organic soil amendments. In addition to the compost treatments, effects of a cover crop of hairy vetch (Vicia villosa Roth) and rye (Secale cereale L.) were evaluated in the organic system from 1999 onward. Pepper growth, harvest weight and marketable fruit numbers were similar in conventional and organic production systems from 1998 to 2000 when 112 kg ha−1 N was applied through synthetic fertilizer or compost. Zone-tillage or incorporation of cover crops prior to planting resulted in pepper weights equivalent to compost treatments in 1999, but in zone-tilled plots in 2000, pepper growth was significantly reduced. Corn borer [Ostrinia nubilalis (Hübner)] larval populations were similar in both systems, with beneficial insect populations greater in the organic system in 1999 only. The number of culled peppers due to insect or disease damage was similar in conventional and organic systems in 1998 and 1999, but greater in the synthetic fertilizer plots in 2000. Postharvest weight loss was similar in the compost (112 kg ha−1 N) and synthetic fertilizer treatments in 1999 and 2000 after three to nine weeks in 10°C storage.

Microbial diversity in hot synthetic compost as revealed by PCR-amplified rRNA sequences from cultivated isolates and extracted DNA

High-temperature (≥60°C) synthetic food waste compost was examined by cultivation-dependent and -independent methods to determine predominant microbial populations. Fluorescent direct counts totaled 6.4 (±2.5)×10 10 cells gdw −1 in a freeze-dried 74°C compost sample, while plate counts for thermophilic heterotrophic aerobes averaged 2.6 (±1.0)×10 8 CFU gdw −1. A pre-lysis cell fractionation method was developed to obtain community DNA and a suite of 16S and 18S rDNA-targeted PCR primers was used to examine the presence of Bacteria, Archaea and fungi. Bacterial 16S rDNA, including a domain-specific 1500-bp fragment and a 300-bp fragment specific for Actinobacteria, was amplified by PCR from all compost samples tested. Archaeal rDNA was not amplified in any sample. Fungal 18S rDNA was only amplified from a separate dairy manure compost that reached a peak temperature of 50°C. Amplified rDNA restriction analysis (ARDRA) was used to screen isolated thermophilic bacteria and a clone library of full-length rDNA fragments. ARDRA screening revealed 14 unique patterns among 63 isolates, with one pattern accounting for 31 of the isolates. In the clone library, 52 unique patterns were detected among 70 clones, indicating high diversity of uncultivated bacteria in hot compost. Phylogenetic analysis revealed that the two most abundant isolates belonged in the genera Aneurinibacillus and Brevibacillus, which are not commonly associated with hot compost. With the exception of one Lactobacillus-type sequence, the clone library contained only sequences that clustered within the genus Bacillus. None of the isolates or cloned sequences could be assigned to the group of obligate thermophilic Bacillus spp. represented by B. stearothermophilus, commonly believed to dominate high-temperature compost. Amplified partial fragments from Actinobacteria, spanning the V3 variable region (Neefs et al. (1990) Nucleic Acids Res. 18, 2237–2242), included sequences related to the genera Saccharomonospora, Gordonia, Rhodococcus and Corynebacterium, although none of these organisms were detected among the isolates or full-length cloned rDNA sequences. All of the thermophilic isolates and sequenced rDNA fragments examined in this study were from Gram-positive organisms.

Microbial diversity in hot synthetic compost as revealed by PCR-amplified rRNA sequences from cultivated isolates and extracted DNA.

High-temperature (>/=60 degrees C) synthetic food waste compost was examined by cultivation-dependent and -independent methods to determine predominant microbial populations. Fluorescent direct counts totaled 6.4 (+/-2.5)x10(10) cells gdw(-1) in a freeze-dried 74 degrees C compost sample, while plate counts for thermophilic heterotrophic aerobes averaged 2.6 (+/-1.0)x10(8) CFU gdw(-1). A pre-lysis cell fractionation method was developed to obtain community DNA and a suite of 16S and 18S rDNA-targeted PCR primers was used to examine the presence of Bacteria, Archaea and fungi. Bacterial 16S rDNA, including a domain-specific 1500-bp fragment and a 300-bp fragment specific for Actinobacteria, was amplified by PCR from all compost samples tested. Archaeal rDNA was not amplified in any sample. Fungal 18S rDNA was only amplified from a separate dairy manure compost that reached a peak temperature of 50 degrees C. Amplified rDNA restriction analysis (ARDRA) was used to screen isolated thermophilic bacteria and a clone library of full-length rDNA fragments. ARDRA screening revealed 14 unique patterns among 63 isolates, with one pattern accounting for 31 of the isolates. In the clone library, 52 unique patterns were detected among 70 clones, indicating high diversity of uncultivated bacteria in hot compost. Phylogenetic analysis revealed that the two most abundant isolates belonged in the genera Aneurinibacillus and Brevibacillus, which are not commonly associated with hot compost. With the exception of one Lactobacillus-type sequence, the clone library contained only sequences that clustered within the genus Bacillus. None of the isolates or cloned sequences could be assigned to the group of obligate thermophilic Bacillus spp. represented by B. stearothermophilus, commonly believed to dominate high-temperature compost. Amplified partial fragments from Actinobacteria, spanning the V3 variable region (Neefs et al. (1990) Nucleic Acids Res. 18, 2237-2242), included sequences related to the genera Saccharomonospora, Gordonia, Rhodococcus and Corynebacterium, although none of these organisms were detected among the isolates or full-length cloned rDNA sequences. All of the thermophilic isolates and sequenced rDNA fragments examined in this study were from Gram-positive organisms.

Effect of environmental parameters on the degradability of polymer films in laboratory-scale composting reactors

Previous research in our laboratory reported a convenient laboratory-scale composting test method to study the weight loss of polymer films in aerobic thermophilic (53°C) reactors maintained at a 60% moisture content. The laboratory-scale compost reactors contained the following synthetic compost mixture (percentage on dry-weight basis): tree leaves (45.0), shredded paper (16.5), food (6.7), meat (5.8), cow manure (17.5), sawdust (1.9), aluminum and steel shavings (2.4), glass beads (1.3), urea (1.9), and a compost seed (1.0) which is designated Mix-1 in this work. To simplify the laboratory-scale compost weight loss test method and better understand how compost mixture compositions and environmental parameters affect the rate of plastic degradation, a systematic variation of the synthetic mixture composition as well as the moisture content was carried out. Cellulose acetate (CA) with a degree of substitution (DS) value of 1.7 and cellophane films were chosen as test polymer substrates for this work. The extent of CA DS-1.7 and cellophane weight loss as a function of the exposure time remained unchanged when the metal and glass components of the mixture were excluded in Mix-2. Further study showed that large variations in the mixture composition such as the replacement of tree leaves, food, meat, and sawdust with steam-exploded wood and alfalfa (forming Mix-C) could be made with little or no change in the time dependence of CA DS-1.7 film weight loss. In contrast, substituting tree leaves, food, meat, cow manure, and sawdust with steam-exploded wood in combination with either Rabbit Choice (Mix-D) or starch and urea (Mix-E) resulted in a significant time increase (from 7 to 12 days) for the complete disappearance of CA DS-1.7 films. Interestingly, in this work no direct correlation was observed between the C/N ratio (which ranged from 13.9 to 61.4) and the CA DS-1.7 film weight loss. Decreasing moisture contents of the compost Mix-2 from 60 and 50 and 40% resulted in dramatic changes in polymer degradation such that CA DS-1.7 showed an increase in the time period for a complete disappearance of polymer films from 6 to 16 and 30 days, respectively.

Broccoli Growth, Yield and Level of Aphid Infestation in Leguminous Living Mulches

ABSTRACT A living mulch is an intercropping system which combines an annual crop with a cover crop in order to achieve better weed and insect control, enhance soil fertility and reduce soil erosion and compaction. In this study broccoli (Brassica oleracea var. botrytis L.) was grown under clean cultivation (no cover crop) and in living mulches using three leguminous cover crops: white clover (Trifolium repens L.), strawberry clover (Trifolium fragiferum L.) and a mixture of birdsfoot trefoil (Lotus corniculatus L.) and red clover (Trifolium praetense L.). Aphid infestation of harvested broccoli heads, leaf area, leaf water content, leaf nitrate-nitrogen and yields were assessed. Fertiliser was applied at commercial rates as synthetic fertiliser or compost crossed with cover crop regime. In plots fertilised with compost aphid infestation on harvested broccoli heads was consistently less in living mulches than under clean cultivation. Nitrogen availability was lower in all compost subplots, as indicated by ...

Button mushroom production in synthetic compost derived from agricultural wastes

Abstract To assist a local button mushroom production industry — in which pre-spawned, pre-packaged synthetic compost was sold to satellite growers — we evaluated various processing parameters, some of which were unique to this type of operation. Corn/oat screenings and urea effectively replaced soybean meal in compost formulations, resulting in higher yields at a lower cost. Sorghum-based spawn contained more inoculum particles than rye-based spawn and, consequently, permitted faster compost colonization. Likewise, the use of higher spawning rates (227–340 g spawn/30 kg compost) resulted in faster colonization. Yield reductions due to improper picking and watering by inexperienced workers was minimized by applying thicker casing soil layers (4·6–5·6 cm); however, this caused mushroom initiation under the casing surface and thereby increased the ratio of dirty mushrooms. Buried perforated tubing was not effective in improving either mushroom yields or quality, as has been demonstrated for porous tubing. A water application rate of 1 liter/box/day appeared sufficient to maintain an adequate moisture reservoir in the casing layer. And finally, to obtain highest yields, the cardboard/plastic bottoms of compost boxes should be perforated to create approximately 1% open space. This allowed sufficient gaseous exchange without drying the compost.

Factors Influencing the Agaritine Content in Cultivated Mushrooms, Agaricus bisporus

Agaritine concentrations were determined in fresh mushrooms grown from various spawn strains on several compost types and harvested at different phases of the cropping cycle. A wild spawn strain produced mushrooms with approximately two times the agaritine content of seven other more commercially important types. Mushrooms harvested from a synthetic compost produced significantly higher amounts of agaritine than five other compost types. Additionally, mushrooms harvested later in the cropping cycle were more likely to have higher agaritine levels compared to earlier harvested mushrooms. Agaritine was also present in the mycelium of Agaricus bisporus growing in liquid culture, but at much lower levels than present in the fruiting bodies.

Development of a synthetic compost for mushroom growing based on wheat straw and chicken manure.

A simple formula for the preparation of synthetic compost to complement existing formulae for the preparation of compost based on horse manure of pig manure is presented, and most of the important factors involved in the preparation are discussed. A synthetic compost with 1000 kg of chopped wheat straw, 1000 kg chicken manure, 60 kg gypsum and over 5000 l water was prepared. The mixture produced 3300 kg of compost. At filling, this compost had a C/N ratio of 18 a pH of 8.6, and contained 2% N and 0.4% NH4. Instead of chicken manure other N-rich organic materials can be used. (Abstract retrieved from CAB Abstracts by CABI’s permission)