Mushroom Industry Research Articles

Spawn Treatment by Cold Plasma for Increase Mushroom Germination and Production

Cold plasma technology has found favour in the agricultural industry for growth stimulating by environmental friendly approach. However, there are still leaking studying of cold plasma technology on the mushroom needs. Current convectional mushrooms germination process requires long duration (∼6 weeks) for fruiting to growth. Therefore, this study aims to investigate the cold plasma efficacy towards the oyster mushroom germination speed and fruiting body production. By using novel atmospheric cold plasma pen system, the mushroom spawn grains were generates towards the spawn. Atmospheric pressure with flow rate of 4, 5 and 6 SLM by considering different duration plasma exposure (0, 5, 15, 30, 45 and 60 seconds) with ∼7 kV of supply voltage was supplied. The efficiency of the treatment was characterised by mushroom cultivation performance particularly on (i) mycelium growth rate and (ii) mushroom fruiting body productions. The results show cold plasma processing parameter, flow rate and treatment time absolutely influence the mushroom germination and production. CP pen system optimized at 5 SLM and 15 s presents triple production of mushroom weight and speed the mycelium growth rate (only 4 weeks) compared to control spawn grains (6 weeks). As conclusion, cold plasma pen system capability applies in mushroom industry.

Evaluation of energy requirements of an industrial scale plant for the cultivation of white button mushroom (<em>Agaricus bisporus</em>)

The white button mushroom (Agaricus bisporus) industry is paying attention to innovation for a more sustainable production and it is getting sophisticated to reach high grade of energetic efficiency coupled with high quality product. For mushroom cultivation the environmental conditions must be controlled therefore in some phases the heat needs to be provided and in other ones it needs to be removed. The objective of this study was to investigate the current growing methodology used at an industrial mushroom farm site for a quantification of energy consumption. Mushroom growing parameters such as temperature and relative humidity were monitored during the production process placing sensors for a continuous data recording of these parameters in different and crucial positions throughout the entire production cycle. Heat is massively produced by the compost/mycelium system and the goal was to quantify the amount of energy needed to remove it through a cooling system and a forced air system that pulls cold air in the cultivation room and picks up the warmer and more humid air. Often, the heat produced by the cultivation room is not enough to reach the optimal growth conditions. In this case the application of an air heating system is necessary. The study was focused on evaluating the energy exchanges during a 41-day period corresponding to a growth cycle of three flushes to quantify the energy requirements of the conditioning system. A total energy of 5483 kWh/cycle was quantified for a mushroom production of 25,000 kg, corresponding to a specific energy requirement of 0.22 kWh/kg, 0.18 for cooling and 0.04 for heating. Results showed that the electric power consumption represents a crucial cost for the mushroom production, therefore an optimization of the energy requirements of the production plant is desirable and it can lead to relevant economic savings. A scenario considering a more efficient air conditioning system was proposed for a more sustainable mushroom production.

A review on valorization of oyster mushroom and waste generated in the mushroom cultivation industry

A review of valorization of oyster mushroom species and waste generated in the mushroom cultivation is presented, with a focus on the cultivation and valorization techniques, conditions, current research status and particularly the hazard mitigation and value-added recovery of the waste mushroom substrate (WMS) - an abundant waste in mushroom cultivation industry. Based on the studies reviewed, the production rate of the present mushroom industry is inadequate to meet market demands. There is a need for the development of new mushroom cultivation methods that can guarantee an increase in mushroom productivity and quality (nutritional and medicinal properties). This review shows that the cylindrical baglog cultivation method is more advantageous compared with the wood tray cultivation method to improve the mushroom yield and cost efficiency. Approximately 5 kg of potentially hazardous WMS (spreading diseases in mushroom farm) is generated for production of 1 kg of mushroom. This encourages various valorization of WMS for use in agricultural and energy conversion applications, mainly as biocompost, plant growing media, and bioenergy. The use of WMS as biofertilizer has shown desirable performance compared to conventional chemical fertilizer, whilst the use of WMS as energy feedstock could produce cleaner bioenergy sources compared to conventional fuels.

The Strategy of Increased Competitiveness and Development Potential in the Region for the Well Being of Community: An Empirical of Oyster Mushroom Industry in Karanganyar, Central Java, Indonesia

Based on the potential of region in Indonesia, each region has a potential flagship industries. Oyster mushroom as one of them of potential in Karanganyar. There is potential that could be developed into an industry so that it is able to improve the welfare of society. In an effort to become Oyster Mushrooms cultivation industry flagship Karanganyar required factor conditions, demand conditions, related and supporting industries, and firm strategy, structure and rivalry so that the oyster mushroom industry be the industry is able to compete.This research is a case study of cultivation of mushrooms, which are descriptive. The object of this research is on the oyster mushroom cultivation in the village of Ngijo, Karanganyar Regency as well as the development of innovative product petrol. The reason for this is because object uses this business originated from trying later evolved and been running 3 (three) years but wanted to create a product variant, so that businessmen need to consider the feasibility of its business worth developed or not.Based on the analysis of the industrial development efforts of oyster mushroom oyster mushroom chips into products quite feasible and innovative as well as provide significant advantages. Practical Implications: Product innovation to make oyster mushrooms that are expected to be received by consumers is the addition of cassava flour white (20%) as to the characteristics of coatings, moisture (1.625%), grey levels (1.622%), levels of protein (16,598%), fat (5,172%), and a score sensory analysis (1,87), yellowish color ( (3,07 fungi), crisp (4,13) and enjoyment the whole 3,80 (like).The research strategy is the done to increase competitiveness and in the development of potential for peoples welfare (study oyster mushroom industry, Karanganyar, Central Java, Indonesia), as applied research and was conducted in object was first.

Effectiveness of current hygiene practices on minimization of Listeria monocytogenes in different mushroom production-related environments.

BackgroundThe commercial production of Agaricus bisporus is a three stage process: 1) production of compost, also called “substrate”; 2) production of casing soil; and 3) production of the mushrooms. Hygiene practices are undertaken at each stage: pasteurization of the substrate, hygiene practices applied during the production of casing soil, postharvest steam cookout, and disinfection at the mushroom production facilities. However, despite these measures, foodborne pathogens, including Listeria monocytogenes, are reported in the mushroom production environment. In this work, the presence of L. monocytogenes was evaluated before and after the application of hygiene practices at each stage of mushroom production with swabs, samples of substrate, casing, and spent mushroom growing substrates.Results L. monocytogenes was not detected in any casing or substrate sample by enumeration according to BS EN ISO 11290‐2:1998. Analysis of the substrate showed that L. monocytogenes was absent in 10 Phase II samples following pasteurization, but was then present in 40% of 10 Phase III samples. At the casing production facility, 31% of 59 samples were positive. Hygiene improvements were applied, and after four sampling occasions, 22% of 37 samples were positive, but no statistically significant difference was observed (p > .05). At mushroom production facilities, the steam cookout process inactivated L. monocytogenes in the spent growth substrate, but 13% of 15 floor swabs at Company 1 and 19% of 16 floor swabs at Company 2, taken after disinfection, were positive.ConclusionThese results showed the possibility of L. monocytogenes recontamination of Phase III substrate, cross‐contamination at the casing production stage and possible survival after postharvest hygiene practices at the mushroom growing facilities. This information will support the development of targeted measures to minimize L. monocytogenes in the mushroom industry.

Determination of the available energy values and amino acid digestibility of Flammulina velutipes stem waste and its effects on carcass trait and meat quality fed to growing-finishing pigs

BackgroundFlammulina velutipes stem waste (FVS) is the by-product of mushroom industry. The objectives of this study were to determine the available energy and amino acid digestibility of FVS fed to pigs, and to evaluate the effects of dietary FVS inclusion on growth performance, biochemical profile of serum, fecal short chain fatty acid (SCFA) concentration, carcass traits, meat quality, intestinal morphology and microflora of pigs. In Exp. 1, twelve crossbred barrows with initial body weight (IBW) of 37.48 ± 4.31 kg were randomly allotted to 2 dietary treatments, including a corn basal diet and an experimental diet containing 24.35% FVS. In Exp. 2, twelve barrows fitted with an ileal T-cannula (IBW: 32.56 ± 1.67 kg) were randomly allotted to 2 dietary treatments, which included a N-free diet and an experimental diet containing 40.0% FVS. In Exp. 3, ninety growing pigs (IBW: 63.98 ± 6.89 kg) were allotted to 1 of 3 treatment diets for 63 d, including a basal diet and 2 experimental diets with 2.5% and 5% FVS, respectively.ResultsThe digestible energy (DE) and metabolizable energy (ME) of FVS were 4.58 and 4.06 MJ/kg on dry matter basis, respectively, and the standardized ileal digestibility (SID) of indispensable AAs ranged from 17.50% to 59.47%. Pigs fed diets with 2.5% FVS showed no difference on average daily gain (ADG) and gain to feed ratio (G/F). Although dietary 5% FVS inclusion impaired apparent total tract digestibility (ATTD) of organic matter and gross energy, it elevated the SCFA concentration (P ≤ 0.04) in gut and antioxidant capacity in serum. In addition, dietary FVS inclusion depressed the backfat thickness (P = 0.03) in pigs. The longissimus dorsi muscle of pigs fed FVS revealed higher n-3 polyunsaturated fatty acid concentration and optimized fatty acid composition. Dietary 2.5% FVS inclusion also improved the intestinal development and health by increasing the villius height to crypt depth ratio (V/C) in jejunum (P < 0.01), and promoting microbial diversity and beneficial microbiota proliferation.ConclusionsIt is feasible to include moderate content of FVS as an unconventional fiber ingredient in diet of growing-finishing pigs.

Pleurotus Mushrooms Content in Glucans and Ergosterol Assessed by ATR-FTIR Spectroscopy and Multivariate Analysis.

Attenuated total reflectance-Fourier transform infrared (ATR-FTIR) spectroscopy was used to monitor the infrared absorption spectra of 79 mushroom samples from 29 Pleurotus ostreatus, P. eryngii and P. nebrodensis strains cultivated on wheat straw, grape marc and/or by-products of the olive industry. The spectroscopic analysis provided a chemical insight into the mushrooms examined, while qualitative and quantitative differences in regions related to proteins, phenolic compounds and polysaccharides were revealed among the species and substrates studied. Moreover, by using advanced chemometrics, correlations of the recorded mushrooms’ spectra versus their content in glucans and ergosterol, commonly determined through traditional analytical techniques, allowed the development of models predicting such contents with a good predictive power (R2: 0.80–0.84) and accuracy (low root mean square error, low relative error and representative to the predicted compounds spectral regions used for the calibrations). Findings indicate that FTIR spectroscopy could be exploited as a potential process analytical technology tool in the mushroom industry to characterize mushrooms and to assess their content in bioactive compounds.

Sterilization of oyster mushroom crop residue substrate by using cold plasma technology

Traditional steaming method applied by mushroom entrepreneurs took long time (48 h) to complete the sterilization process. Moreover, improper steaming process causes contamination by soil-borne pathogens. This study will develop a new design by using cold plasma technology for crop residue substrate sterilization process. The cold plasma discharge works as sterilization able to kill the soil-borne pathogens without effect the substrate properties. Hence, focus was intention to examine the efficiency of the dielectric barrier discharges cold plasma (DBD-CP) pen mixer system on the crop residue substrate sterilization process for oyster mushroom cultivation. This renewal process develops by using electric field from voltage breakdown to discharge the plasma. The plasma with variable sterilization duration of 0 min, 5 min, 10 min, 15 min, 20 min and 25 min will discharge on the crop residue substrate. The soil-borne pathogens inactivation occupies on agro-waste substrate will examine using bacteria colony forming unit (CFU) method. Data gathered shows the bacteria colonies reduce from 1.0 9 CFU/mL (0 min) to 1.5 8 CFU/mL (25 min) due to increment of sterilization time. The mushrooms cultivation duration also characterized. The mushroom fruiting body was successfully growth two days earlier on crop residue substrate sterilized using cold plasma technology. Results show 25 min of sterilization duration by cold plasma technology shows the best optimum time. As conclusion, cold plasma technology is an efficient technology and can be applied in oyster mushroom industry for crop residue substrate sterilization process. The mushroom productivity was increase, the mushroom fruiting body growth faster, the sterilization time was shorter and the soil-borne pathogens were reduced.

Evaluation of Fresh Mushroom Compost in a Field Corn Production System

Commercial mushroom producers are continually looking for new substrate raw material sources and pathways to dispose of mushroom compost (formerly called “spent mushroom substrate”) after crop completion. A relatively new material used in the mushroom industry is corn stover, but supplies are somewhat limited. Corn farmers are often reluctant to remove stover from fields because of nutrient loss and possible soil erosion due to reduced soil protection, however, mushroom compost may be a potential substitute for stover. This field study evaluated the potential to improve corn crop yield and soil quality through stover removal coupled with the soil surface application of fresh mushroom compost. Stover was removed in amounts of 0, 70, and 100% and replaced with fresh mushroom compost at rates of 0, 5, 10, 20, and 40 tons per acre to find an optimal rate for both, and to provide a rationale to replace stover with mushroom compost in order to generate additional income for corn farmers, and increase substrate component availability and mushroom compost disposal alternatives, to the mushroom industry. The results showed that corn stover removal did not influence corn yield, but an increase in corn yield trend was observed with the application of an increasing amounts ≥ 20 tons fresh mushroom compost per acre. Analysis of soil parameters, at 0-2 inch and 2-8 inch rootzone depths, at the start of the field study compared to approximately one year later were mostly inconclusive. Of note, the addition of ≥ 5 tons fresh mushroom compost per acre resulted in an increase in soil pH at 0-2 inch depth.

Effects of apple and pear wood vinegar components on Pleurotus ostreatus mycelium growth

In order to facilitate the application of wood vinegar in the mushroom industry, a framework was developed to reveal the individual and interactive effects of chemical groups in wood vinegars on Pleurotus ostreatus mycelium growth. By a series of refining and separating methods, the crude wood vinegar samples were processed and separated into six subgroups with distinctive component concentrations in each. Adding the wood vinegar subgroups into the culturing medium resulted in differences in mycelium growth. Analysis of variance was performed on the differences to evaluate the effects of seven chemical groups on mycelium growth. The enhancing effects of groups of chemicals were (ranked by effect) alcohols &gt; esters &gt; aldehydes; the inhibiting groups of chemicals were phenols &gt; ketones &gt; acids. The principle inhibitory chemicals in the wood vinegars were most likely 1,2-benzenediol, 2-methyl phenol, and 4-ethyl-2-methoxyphenol. The synergistic effects between acids and phenols and between acids and ketones were confirmed. By these effects, the inhibiting chemicals interacted synergistically as mycelium growth promoters.

Agribusiness Strategy: Adding Value to the Mushroom Value Chain

Strategy should begin with the understanding of customer needs which can be determined through perceptions of channel partners or direct research. In line with this, the study conducts a qualitative value chain audit of the mushroom industry with a view to understanding priorities. Structured and semi-structured interviews were conducted with value chain players of the 'mushroom growers and export association'. Value chain participants prioritised changing customerperceptions to improve demand, and to grow the market through penetration and the management of factors that influence the marketing mix, and the provision of quality inputs to improve production and influence the need to address the problem of access to finance and a strong association that advocates for matters of the industry. The study concludes that qualitative value chain analysis of participants' perspectives provides the means for understanding of priority activities for value creation. The study recommends further quantitative value chain analysis that measures the actual value that prioritised value chain activities could generate.&#x0D; Keywords: Agribusiness; mushroom; value chain, strategy, qualitative.

A Review on the Potential Reuse of Functional Polysaccharides Extracted from the By-Products of Mushroom Processing

Mushrooms contain many types of nutrients; they are widely regarded as healthy food product. The development of the global mushroom industry has resulted the production of by-products such as stipes, discarded space bags, and broken fruiting bodies. Mushroom by-products account for approximately 20% of mushroom weight and have a high recycling value. Mushroom by-products are most commonly used as compost and animal feed. They contain large amounts of polysaccharides, triterpenes, ergosterol, glycoproteins, dietary fiber, and other components from which functional components could be extracted. Among those components, polysaccharides have been widely studied. This review paper evaluated current research findings, which revealed that new extraction techniques such as microwave, ultrasound, pulsed electrical fields, and high pressure could be used to increase the efficiency of polysaccharide recovery from mushroom by-products. We also separately discussed the functionality of various types of polysaccharides extracted from different mushroom by-products with regard to immune regulation, alleviation of cardiovascular disease, protection of intestinal health, as well as anticancer, antibacterial, and other health promoting effects. This review highlights that mushroom waste contains many types of functional polysaccharide components that have potential applications in foodstuffs and medicine. The use of new extraction techniques can improve the utilization of whole mushrooms. Effective recovery of polysaccharide components from mushroom by-products can increase the overall value of mushroom cultivation and decrease the production of agricultural waste.

Log and bag cultivation of Oyster (Pleurotus ostreatus) and Lingzhi (Ganoderma lucidum) mushrooms in Cambodia

The development of the mushroom industry in Cambodia through the production of oyster (Pleurotus ostreatus) and lingzhi (Ganoderma lucidum) species requires local knowledge about growth rates, quality control, disease management and other biological characteristics to be produced. This study compares the growth rate and yield of these species in both bag and log cultures. Mushrooms were cultivated by transferring tissues from P. ostreatus and G. lucidum strains to potato dextrose agar (PDA) plates. Then, these strains were multiplied through transferring their spawn to successive grain bottles. Finally, the spawn was harvested and transferred to either plastic bags filled with sawdust (rubber tree) or prepared logs. In the case of the strains grown in logs, 19 of the P. ostreatus cultures and 22 of the G. lucidum cultures were contaminated; while this occurred for only 5 and 13 of the bag cultures, respectively. Different mushroom species require different growing conditions. For instance, P. ostreatus strains thrive at a temperature between 20°C and 30°C at 70 to 90% humidity. However, G. lucidum strains thrive at a temperature between 18°C and 25°C, at a humidity of 85 to 90%. The choice of substrate also affects yield. In the Cambodian context, a sawdust substrate was found to produce higher yields, in terms of both biological efficiency and the number of fruiting bodies. It is recommended that the cultivation of P. ostreatus on a sawdust substrate is promoted to rice farmers in Cambodia.

Adsorption characteristics of Pb(II) using biochar derived from spent mushroom substrate

As a multifunctional material, biochar is considered a potential adsorbent for removing heavy metals from wastewater. Most biochars with high adsorption capacities have been modified, but this modification is uneconomical, and modifying biochar may cause secondary pollution. Thus, it is necessary to develop an efficient biochar without modification. In this study, spent P. ostreatus substrate and spent shiitake substrate were used as the raw materials to prepare biochar. Then, the physicochemical properties of the biochars and their removal efficiencies for Pb(II) were investigated. The results showed that the physicochemical properties (e.g., large BET surface area, small pore structure and abundant functional groups) contributed to the large adsorption capacity for Pb(II); the maximum adsorption capacities were 326 mg g−1 (spent P. ostreatus substrate-derived biochar) and 398 mg g−1 (spent shiitake substrate-derived biochar), which are 1.6–10 times larger than those of other modified biochars. The Pb(II) adsorption data could be well described by the pseudo-second-order kinetic model and the Langmuir model. This study provides a new method to comprehensively utilize spent mushroom substrates for the sustainable development of the edible mushroom industry.

Development of Lycoriella ingenua and Bradysia impatiens on different phases of agaricus composts

Fungus gnats are small, dark colored, mosquito like fragile insects. They can be encountered all around the world, excluding places with extreme climate. Gnats prefer habitats that are damp with high relative humidity and rich in organic debris. Most of the species are not considered to be harmful in agriculture, but some may cause serious damage, especially in forcing of vegetable or ornamental plants. In mushroom production, however, they are considered as the most destructive pests; the damage caused by them alone can result in huge loss for mushroom farmers. In the Hungarian mushroom industry, fungus gnats damage mainly white-button mushroom, oyster mushroom and pioppino productions. Lycoriella ingenua (Dufour, 1839) and Bradysia impatiens (Johannsen, 1912) are the two most commonly found fungus gnat species from the family Sciaridae on Hungarian mushroom farms.&#x0D; We have conducted an experiment with the two aforementioned species, to find out, whether they can fully develop into adults, feeding purely on Agaricus compost diet. We used unspawned white button mushroom compost (phase 2) and spawned compost which has been colonized by the mycelia of Agaricus bisporus (phase 3). We did not conduct any experiment with the first compost phase, as it undergoes pasteurization, which eliminates any pests in it. We recorded emerging gnats only from phase 2 compost. Neither L. ingenua, nor B. impatiens could complete its development on phase 3 compost diet, furthermore not even pupae were observed in these breeding pots. From pots containing phase 2 compost, a total of 1607 adults emerged. The number of B. impatiens adults was 653, and 954 for L. ingenua. Sex ratios for the two species were different. For B. impatiens, the number of females was 1.36 times greater than that of males, in L. ingenua there were 1.7 times more males than females in total. Swarming took approximately 6 days for B. impatiens and 10 days for L. ingenua. From the experiment we can conclude that phase 3 compost, which is well interwoven with Agaricus bisporus mycelia is not suitable for B. impatiens and L. ingenua to complete their whole life cycle.

Economic assessment of the development potential of mushroom production in the Russian Federation

The article assesses the issue of further development of the industrial mushroom production in the Russian Federation in order to fulfill the objectives of the State Program for the Development of Agriculture and Regulation of Agricultural Products, Raw Materials, and Food Markets for 2013-2020. It was developed in accordance with the principles of ensuring food independence of Russia, sustainable development of rural territories of the Russian Federation, and financial sustainability of agricultural producers. Conducting an analysis of the state of the world mushroom industry, general trends in the organization of industrial enterprises, and the choice of modern technological solutions, which are the basis for the intensification of production and its economic efficiency. The article assesses a level of self-sufficiency of the Russian Federation in mushroom products on the basis of a comparison of the consumption levels of cultivated mushrooms in the developed European countries, the USA, as well as East and Southeast Asia.

Sustainable use of the spent mushroom substrate of Pleurotus florida for production of lignocellulolytic enzymes.

Spent mushroom substrate (SMS), a major byproduct of the mushroom industry, is a lignocellulosic biomass, which contains approximately 57-74.3% of holocellulose fraction. This study was aimed at utilizing SMS of Pleurotus florida for recovery of lignocellulolytic enzymes and sugars and also as a substrate for production of cellulolytic enzymes using different isolates of Trichoderma and Aspergillus under solid-state fermentation (SSF). SMS of P. florida extracts contained significant amounts of laccase (3,015.8 ± 29.5 U/g SMS) and xylanase (1,187.9 ± 12 U/g SMS) activity. Crystallinity pattern and chemical changes in SMS revealed that SMS had a lower crystallinity index (34.2%) as compared with the raw biomass (37.8%), which, in turn, helps in enhancing the accessibility of cellulolytic enzymes to holocellulose. Among the isolates, Trichoderma longibrachiatum A-01 showed maximum activity of endoglucanase (220.4 ± 5.9 U/mg), exoglucanase (78.5 ± 3.2 U/mg) and xylanase (1,550.4 ± 11.6 U/mg) while Aspergillus aculeatus C-08 showed maximum activity of cellobiase (113.9 ± 3.9 U/mg). Extraction with sodium citrate buffer (pH 4.8) showed maximum cellulolytic enzyme activity as compared with other solvents tested. Partial purification of endoglucanase, exoglucanase, xylanase, and cellobiase resulted in 56.3% (1,112.5 U/mg), 48.4% (212.5 U/mg), 44% (4,492.3 U/mg), and 62% (705.0 U/mg) yield with an increase by 5.2-, 4.5-, 4.1-, and 5.0-fold as compared with crude extract. The results reveal that SMS from P. florida could be a potential and cost-effective substrate for production of cellulolytic enzymes from T. longibrachiatum A-01 and A. aculeatus C-08.

The ability of Listeria monocytogenes to form biofilm on surfaces relevant to the mushroom production environment

Due to its ubiquitous nature, Listeria monocytogenes is a threat to all fresh fruits and vegetables, including mushrooms, which are Ireland's largest horticultural crop. Although fresh cultivated mushrooms (Agaricus bisporus) have not been previously linked with listeriosis outbreaks, the pathogen still poses a threat to the industry, particularly due to its ability to form biofilms. This threat is highlighted by the multiple recalls of mushroom products caused by L. monocytogenes contamination and by previous studies demonstrating that L. monocytogenes is present in the mushroom production environment. In this study, the biofilm formation potential of L. monocytogenes strains isolated from the mushroom production environment was investigated on materials and at temperatures relevant to mushroom production. A preliminary assessment of biofilm formation of 73 mushroom industry isolates was undertaken using a crystal violet assay on polystyrene microtitre plates. The biofilm formation of a subset (n = 7) of these strains was then assessed on twelve different materials, including materials that are representative of the materials commonly found in the mushroom production environments, using the CDC biofilm reactor. Vertical scanning interferometry was used to determine the surface roughness of the chosen materials. All the strains tested using the CDC biofilm reactor were able to form biofilms on the different surfaces tested but material type was found to be a key determining factor on the levels of biofilm formed. Stainless steel, aluminium, rubber, polypropylene and polycarbonate were all able to support biofilm levels in the range of 4–4.9 log10 CFU/cm2, for seven different L. monocytogenes strains. Mushroom industry-specific materials, including growing nets and tarpaulins, were found to support biofilms levels between 4.7 and 6.7 log10 CFU/cm2. Concrete was found to be of concern as it supported 7.7 log10 CFU/cm2 of biofilm for the same strains; however, sealing the concrete resulted in an approximately 2-log reduction in biofilm levels. The surface roughness of the materials varied greatly between the materials (0.7–3.5 log10 Ra) and was found to have a positive correlation with biofilm formation (rs = 0.573) although marginally significant (P = 0.051). The results of this study indicate that L. monocytogenes can readily form biofilms on mushroom industry relevant surfaces, and additionally identifies surfaces of specific concern, where rigorous cleaning and disinfection is required.

Pseudomonas sp. UW4 acdS gene promotes primordium initiation and fruiting body development of Agaricus bisporus.

To simplify industrial mushroom cultivation, we introduced a bacterial Pseudomonas sp. UW4 acdS gene, encoding 1-aminocyclopropane-1-carboxylic acid (ACC) deaminase (AcdS), into fungus Agaricus bisporus. Transformant A. bisporus-acdS14 cased with sterilized-vermiculite generated primordia 5days sooner than wild-type strain, confirming the specific role of the AcdS enzyme. Being consistent with the AcdS enzyme activity increased by 84%, the mycelium growth rate was increased by 25%; but, the ACC and ethylene concentrations were reduced by 71% and 36%, respectively, in the A. bisporus-acdS14 transformant. And the bacterium P. sp. UW4 attachment on the mycelium of the A. bisporus-acdS14 transformant was drastically reduced. We conclude that the heterogeneously expressed bacterial acdS gene degrades ACC and reduces ethylene-synthesis, eliminating ethylene inhibition on the mycelium growth and primordium formation in A. bisporus. Our results provide new insights into the mechanism underlying casing soil bacterium, and help formulate a casing-less cultivation for the next-generation mushroom industry.

Foliar application of nitrogenous compounds and elicitors to Tempranillo grapevines: Microbiological implications

This study was aimed to analyze the effects of the nitrogen foliar application, and elicitation used on microbial populations of musts. The nitrogenous compounds were raw and treated wastewater from mushroom industry and a commercial yeast derivate; the elicitors were methyl jasmonate, chitosan and one commercial elicitor from a yeast source. Those six products were sprayed as pre-harvest treatment over the leaves of Tempranillo grapevines for improving quality and maturity of grapes. The applications of raw and treated wastewaters from mushroom industry, chitosan and methyl jasmonate elicitation did not cause changes in microbial diversity of must samples. In contrast, spraying commercial yeast derivate products made the must microbiota reach a high richness of species that would be positive in ecological terms. This research succeeded in establishing the impacts of foliar applications in the grapevines on the microbial community, and in any case, negative impacts were observed so that, presumably, these foliar applications can be perfectly implemented as agronomic practice.