Substrate Sterilization Research Articles

Impact of three distinct mycorrhizal species on Cedrus libani seedling development and nutrient uptake

Aim of study: In semi-arid afforestation sites, the study aimed to create mycorrhizal seedlings with high vitality, health, and tolerance to harsh environments. The study's hypotheses state that mycorrhizal inoculation will improve Cedrus libani (Taurus cedar) seedlings' growth characteristics, nutrition, root colonization, and mycorrhizal reliance. Area of study: The Eastern Mediterranean Research Institute laboratory and greenhouse in Tarsus district-Mersin, Türkiye. Material and methods: The experiment involved inoculation of three ectomycorrhizal fungal species (Lactarius delicious, Hebeloma crustuliniforme, Tricholoma ustale) collected from natural cedar stands on to cedar seedlings grown in two different substrates (sterilized, non-sterilized. Inoculation was carried out by dipping the roots of Cedrus libani A. Rich (Taurus cedar) seedlings into mycorrhizal mycelia. Main results: Cedar seedlings infected with mycorrhiza exhibited a greater biomass ratio in comparison to the control seedlings. Substrate sterilization increased seedling growth variables. The highest growth, some nutrients such as N, P, K, Fe and Zn uptake, root colonization and mycorrhizal dependence occurred in seedlings with H. crustuliniforme and L. delicious. Research highlights: Although this study is limited to Taurus cedar-mycorrhiza combinations, it may also be applicable to different mycorrhizal fungal species and many other valuable host tree species. More research is needed on the adaptation of different mycorrhizal species to habitats to increase the success of afforestation efforts in arid and semi-arid regions.

EVALUATION OF DIFFERENT PASTEURIZATION AND STERILIZATION METHODS FOR OYSTER MUSHROOM SUBSTRATES

Oyster mushrooms can be cultivated with great spatial efficiency, on nutrient-poor plant materials, without light and under diverse climatic conditions. Their production therefore has a great potential for improving food security, especially in impoverished and overpopulated areas. However, the pasteurization or sterilization of mushroom substrates uses a lot of energy and water. This study investigates the impact of different pasteurization and sterilization techniques on the growth and yield of oyster mushrooms, and evaluates their water and energy usage. The efficacy of heat-based methods, including hot water, hot air, and pressurized steam, as well as a chemical method utilizing hydrated lime (Ca(OH)2) were assessed. The results show that sterilizing mushroom substrates through autoclaving can significantly increase the dry yields, up to 50% compared to pasteurization methods. However, pasteurization methods also achieved excellent results compared to untreated substrates, with good harvests and low pest occurrence. The mushroom water content was significantly higher in pasteurization methods where the substrate is submerged in water. In terms of fresh yield, hot water pasteurization was as good as autoclaving and significantly better than the other pasteurization methods. Hot air pasteurization has, on balance, a better water and energy efficiency than autoclave sterilization (about 75 % less energy) or hot water pasteurization (about 85 % less water). When performed at an air temperature of 75° C, which was found to be sufficient for successful mushroom cultivation, as little as 1068 kJ was needed to pasteurize one kg of dry substrate (e.g. maize straw). While hydrated lime pasteurization could use as little as 270 kJ per kg of dry substrate, it is very wasteful of water, as is hot water pasteurization and could lead to nutrient leaking. The success of mushroom cultivation, especially with hot air pasteurization, could also be influenced by the duration of substrate soaking before treatment. The study provides slight evidence, although inconclusive, for a positive effect of prolonged soaking periods on yield. Lastly, the study discusses the applicability of different disinfection techniques at varying production scales and for different mushroom species, focusing on African countries, where comparably small mushroom economies are growing rapidly, but often through the use of unsustainable pasteurization technology.

Influence of Funneliformis mosseae in the growth and accumulation of dry biomass in Dalia plants

Objetive: in the production of Dahlia spp., only chemical fertilization has been used, and an option that has not yet been explored is the implementation of a microbial inoculant. Therefore, the objective of this study was to evaluate the effect of the mycorrhizal fungus Funneliformis mosseae on the growth and development of the dahlia (Dahlia variabilis var. Variegated dwarf). Design/methodology/approach: the seeds were sown in polyethylene bags containing a mixture of black soil, peat moss, and agrolite. A completely randomized design was used, and the treatment structure was 2x3 factorial. The study factors were F. mosseae, chemical fertilization, and substrate sterilization. Results: an analysis of variance was performed, and the mean values of the treatments were compared with Tukey’s test (α = 0.05). Conclusions: with the inoculation of F. mosseae, a significant increase was obtained in the study variables: plant height, stem diameter, number of buds and flowers per plant; leaf + stem, flower, root, and total biomass, compared to non-inoculated plants. A colonization of 89 % in the roots was recorded. A limitation of the study is that the effect of the inoculum on plant growth can vary according to the mycorrhiza species used. In conclusion, inoculation with Funneliformis mosseae increased growth and biomass accumulation in Dahlia plants.

Optimizing growth chamber conditions for maintaining Arcticlichen‐dominatedbiocrusts

Optimizing growth chamber conditions for Arctic lichen biocrusts will create new opportunities to assess and prioritize reclamation techniques given the challenges associated with conducting arctic field work. Our study is the first to examine growth chamber conditions for optimizing survival and growth of Arctic lichen biocrusts, as measured by changes in lichen cover. We assessed effects of substrate crossed with substrate depth, substrate sterilization, lichen inoculation and community composition, and watering frequency in four concurrent experiments over 6 weeks on survival of arctic biocrusts collected from Diavik Diamond Mine Inc., Northwest Territories, Canada. Mixed species declined less thanFlavocetraria cucullata, and substrate affectedF. cucullatasurvival over time. Live lichen cover declined least with a 3‐day watering frequency and substrate depth of 1 cm. Sterilization did not affect lichen survival, and no contamination was observed over 6 weeks. Our results highlight the challenges of maintaining and growing lichens under controlled conditions, as only a few treatments showed increases in cover. Our research shows that even short‐term growth chamber experiments have potential to screen reclamation treatments prior to field assessments, permitting reclamation scientists to optimize limited time and resources while in the field.

Influence of Heat Treatment and Solid-State Fermentation on the Lignocellulosic Fractions of Substrates Supporting Lentinula edodes (Berk.) Pegler Cultivation: Implications for Commercial Production

Mushroom production in India has registered a considerable growth in the recent times. However, cultivation of shiitake mushroom, which represents a major share at a global level, is still at a primitive stage in the Indian subcontinent. The scarcity of raw materials and the cost of energy for substrate sterilization are the major hurdles for a large-scale production. The present study delves into the possibility of growing shiitake mushroom on lignocellulosic biomass (saw dust and wheat straw) processed with different heat treatments to develop a cost-effective production technology. Six different strains of shiitake mushroom, viz., DMRO-35, 51, 297, 388s, 410, 412, were used in this study. The substrates were exposed to a pasteurization temperature of 80 ± 5 °C in a bulk pasteurization chamber for three different times (H1–H3) and also to a high-pressure sterilization (H4) in an autoclave. DMRO-388s was found to be the most productive strain, irrespective of the substrate and heat treatment method used. Significant differences were observed in the biological yield depending on the type of substrate and heat treatment. Changes in the biochemical composition of the lignocellulosic residues in three different stages, viz., pre heat treatment, inoculation and primordial formation stages, were recorded. Changes in heat treatment levels and duration significantly altered the cellulose/lignin ratio of the growing substrate. High-pressure sterilization aided the rapid degradation of lignin in the substrate and increased its bioavailability, thereby facilitating the fungus achieving its potential yield. A significant correlation in the positive direction between the yield levels of the tested strains and the consumption of lignin in the growing substrate was found, suggesting the significance of pre heat treatment for the bioconversion of lignin and its subsequent utilization in the solid-state fermentation process. The substrate pre heat treatment under high-pressure sterilization was proved to be beneficial to obtain the maximum yields of shiitake mushroom.

Mycorrhizal Inoculation Effect on Sweet Potato (Ipomoea batatas (L.) Lam) Seedlings

Sweet potato is an increasingly significant crop and its effective and sustainable cultivation has become important in temperate countries. The purpose of this pilot study was to investigate the effects of a mycorrhizal inoculum, Symbivit, and whether it could establish a symbiotic relationship with the seedlings of two sweet potato varieties (orange and purple). The effectiveness of the mycorrhizal inoculation with a sterilized substrate on the mycorrhizal parameters (F%, M%, m%, a%, A%) and physical parameters “[length of roots and shoots (cm), the fresh weight of shoots and roots (g) as well as the length of stem (cm)]” on the sweet potato seedlings has also been studied. Results show that the sterilization treatment with Symbivit in both varieties increased the frequency of mycorrhiza in the root system. For the intensity of the mycorrhizal colonization in the root fragments and the arbuscular abundance, there was a difference between the mycorrhizal inoculum and the sterilization treatment among the varieties. Overall, the preliminary results provided remarkable information about mycorrhizal inoculation, substrate sterilization on mycorrhizal development, as well as changes in the physical parameters between sweet potato seedlings. Our results could serve as a practical strategy for further research into adding significance to the effect of the beneficial soil microbes on sweet potatoes.

Impact of the surface modifications and cell culture techniques on the biomechanical properties of PDMS in relation to cell growth behavior

PDMS is the most widely used material in the microfluidic systems because of its advantageous properties including ease of manufacture, low cost, transparency, and gas permeability. Although all biomaterials need to be sterilized for usage for in vitro or in vivo systems to avoid possible contaminants, none of them proved effective in providing the gold standards so far for PDMS sterilization. Therefore we evaluated the influence of both UV and ethanol sterilization of PDMS substrates on the cell behavior via investigating cell proliferation, oxidative stress and nutrient metabolism of 293 T cells growing on the PDMS first time in the literature. Modulus of elasticity and stress relaxation of UV-treated PDMS samples increased compared to the ethanol-treated ones leading to a state of surface stiffness preferable for cell growth and proliferation. Oxidative stress metabolism of cells growing on the UV-treated PDMS was more stable compared to the ethanol-treated samples. Trace element and mineral metabolism are not impaired in the cells growing on the UV-treated PDMS samples. First time in the literature, we showed that UV treatment is more suitable for the PDMS samples used in the cell culture experiments.

Solarisation – An effective low cost substrate sterilization technique for the cultivation of milky mushroom (Calocybe indica)

The increasing crop production is generating huge amount of agricultural waste creating serious environmental pollution and hazards. The agro wastes composed of lignin are the recalcitrant fractions which pose serious threat to nature. Utilization and recycling of agro waste in mushroom cultivation is one the eco-friendly profitable venture. In this context a study was conducted to evaluate the biological efficiency of milky mushroom production by utilising agro wastes as substrates subjected to different sterilisation procedures. The substrates used were paddy straw, spent mushroom substrate (SMS), and coir pith subjected to sterilization procedures viz., boiling, solarisation and chemical method. Solarisation of substrates SMS and paddy straw gave better mycelial growth and took minimum period for spawn run, initial production and harvest. SMS gave more number of sporophores and yield when compared to paddy straw and coir pith. Solarisation was the best sterilisation procedure for obtaining higher yield of milky mushroom. The coir pith substrate subjected to solarisation and boiling showed heavy incidence of contaminants viz., Trichoderma and Coprinus. The solarised SMS was the best substrate and sterilisation combination in producing higher yield of milky mushroom.

EFFECT OF NATURAL AND SYNTHETIC PHYTOHORMONES ON GROWTH AND DEVELOPMENT OF HIGHER BASIDIOMYCETES

The paper is aimed to analyze the current data on the influence of exogenous growth stimulators on growth and development of higher Basidiomycetes. The historical aspects about discovery and role of phytohormones in fungi physiology are reviewed. The taxa of the basidiomycetes, which are capable of synthesizing phytohormones of all known types, including Aphyllophorales, Boletales, Agaricales, Sclerodermales, Hymenogastrales, Uredinales, Ustilaginales are described. The data from different sources describing the effects of natural and synthetic growth stimulators on the development of basidiomycetes are summarized and compared. It is noted that various concentrations of phytohormones (auxins, gibberellins, cytokinins) from 0.01 to 400 mg/ml were used in the experiments to study their effects on mycelial growth. Possible causes of conflicting results obtained by different authors, such as application of diverse methods of mushroom cultivation, different media and methods of substrate sterilization, are described.

Effects of composition, age and sterilization techniques of mother culture on the growth and yield of Volvariella volvacea (Bull.) Singer

The research work was carried out to investigate the efficacy of different mother culture media viz., rice straw (T-1), rice straw and rice bran (T-2), rice husk (T-3), rice grain (T-4), maize grain (T-5), and rice straw and wheat bran (T-6) and the impact of age of mother culture and substrate sterilization techniques viz., sun dried for 8 hrs covering with transparent polythene (A-1), black polythene (A-2), blue polythene (A-3) sheet, autoclave for two hrs at 121°C (A-4), and hot water for one hr (A-5) for the commercial cultivation of Volvariella volvacea (Bull.) Singer. The maximum mycelium run rate and minimum days required for completing the mother culture were recorded in T-4. The lowest days required for primordial initiation (DRFPI) was 6 in T-1 and T-2, whereas highest DRFPI was recorded in T-3. The maximum (13.33) days required for first harvest (DRFFH) and lowest (109) number of effective fruiting bodies (NEFB) were recorded in T-3. The minimum (10.67 days) DRFFH was found in T-2 and maximum (239.30) NEFB was recorded in T-1. The lowest length and diameter (LFB and DFB) were recorded in T-5 (3.03 cm) and T-1 (1.66 cm), while highest LFB and DFB were observed in T-3 (3.20 and 2.39 cm). Maximum biological yield and efficiency were observed in rice straw and wheat bran materials. The highest NEFB, DFB, biological yield and efficiency were recorded in 30 days old of mother culture. The results revealed that combined rice straw and wheat bran were the excellent mother culture medium and 30 days old was the best age for the commercial production of paddy straw mushroom. Considering the experimental results on the sterilization techniques it may be suggested that hot water sterilization of rice straw substrate was the best sterilization technique for the commercial production and yield improvement of V. volvacea.

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.

A study on the growth characteristics of pleurotus sajor-caju with varying substrate sterilization methods and days of spawn maturity

The research work carried out investigated the influence of various substrate sterilization methods and days of spawn maturity on the growth characteristics of Pleurotus sajor-caju, grey oyster mushroom. The paddy straw substrate was sterilized by various sterilization methods such as chemical sterilization, boilingwater sterilization and steam sterilization. The spawn of the mushroom produced were used at three different days of maturity viz. 25 days, 35 days and 45 days. The substrate and spawn inoculated beds were maintained at defined environmental conditions in the mushroom cultivation chamber and the growthperformance were monitored and the characteristics were recorded. The study revealed that the steam sterilized substrate and the 35 days old spawn gave the maximum yield compared to the beds inoculated with substrates sterilized with other two methods of sterilization and spawn of 25 days and 45 days old. Theresults gave a reliable information regarding the preference of the substrate sterilization method and the days of spawn maturity for the cultivation of the Pleurotus sajor-caju, grey oyster mushroom.

Effect of Substrate Sterilization and Spawning Method on the Yield and Yield Attributes of Milky White Mushroom (Calocybe indica)

Sterilization of uncomposted substrate is necessary to avoid contamination and promote mycelium growth for getting maximum yield of mushroom. Spawning method is also important for evenly growth of mycelium in the substrate. Therefore, the present experiment was carried out to investigate the impact of substrate sterilization technique and spawning method on yield and yield attributes of C. indica. Seven different treatments such as Steam treatment of substrate and spawning in 3 layers (T1), Steam treatment of substrate and spawning thoroughly (T2), Autoclaving of substrate and top spawning (T3), Autoclaving of substrate and spawning in 3 layers (T4), Autoclaving of substrate and spawning thoroughly (T5), Hot water treatment of substrate and spawning in 3 layers (T6) and Hot water treatment of substrate and spawning thoroughly (T7) were used in this experiment. Mycelium colonization, substrate contamination, days to total harvest, yield and biological efficiency was significantly affected by substrate sterilization technique and spawning method. Faster mycelium colonization, no substrate contamination, highest yield and biological efficiency was recorded in substrate treated with hot water and inoculated in three layers (T6). Result revealed that hot water treatment in combination with three layer spawning of rice straw substrate was the best substrate sterilization technique & spawning method for milky white mushroom cultivation.

Biogenic synthesis of silica nanoparticles from corn cobs husks. Dependence of the productivity on the method of raw material processing.

Corn processing generates thousands of tons of cob husks, which still contains many valuable elements. To make the most of these wastes, they are applied as substrates for biotransformation's procedures. This approach allowed converting or releasing, the elements deposited in the plant material and obtaining valuable products. Thus bioconversion of corn cob husks (CCH) using a fungus of the Fusarium culmorum genus resulted in obtaining silica nanoparticles of defined size and morphology. SEM analysis excluded their presence on the surface of the substrate. FTIR confirmed the presence of siloxane bonds and O-Si-O bonds in post-biotransformation fluid. Using the Heteropoly Blue Method, it was checked that the highest concentration of silica during 16-day biotransformation falls on the 7th day of the process, in which both the substrate sterilization and the process of the biocatalyst starvation were of key importance. Using the STEM and EDX analysis, it was proved that the obtained nanoparticles with a spherical form are structured and their dimensions are ~40 and ~70nm. ICP-OES proved that the overall process efficiency was 47%. Such nanoparticles can be successfully used in the medical industry.

Comparative study of oyster mushroom cultivation by physical and chemical method of sterilization

Mushroom is a crop which is cultivated in many countries using different agricultural wastes. Oyster mushroom can be cultivated by using two types of substrates such as sawdust, straw. Effect of different sterilization techniques of substrate on yield of P. sajor caju, an experiment was laid out by treating paddy straw substrate with hot water, steam and chemicals. No treatment was subjected to the control. The experiments were laid out in completely randomized block design with six replication and four treatments viz. T1 = In hot water treatment-substrate after presoaking for four hours, was immersed in hot water (80 0C +5 0C) for one hour, T2= In steam sterilization treatment, presoaked substrate was rapped in gunny bag and autoclaved at 15 lbs p.s.i. for one hour., T3 =In chemical sterilization, substrate was immersed in 75ppm carbaendazim (50 w.p.) + 500 ppm formaline (40%) solution for 18 hours and T4= In control treatment – substrate steeping was done in plane water for 18 hours. During the both year experiment results are indicated that the treatment of chemical sterilization of substrate enhanced the spawn run which was completed in 21 days as compared to control (23 days) during both the years. It was followed by hot water substrate treatment (22 days) and steam sterilization of substrate (23 days) during both the years. The first harvest was also hastened 2 days by chemical sterilization followed by steam sterilization. As regards yield, all the treatments produced significantly higher yield than control. Chemical treated substrated produced maximum and significantly higher yield (420.00g and 418.0g) than other treatments during both the years.

Substrate sterilization with thiophanate-methyl and its biodegradation to carbendazim in oyster mushroom (Pleurotus ostreatus var. florida).

Residue analysis to detect thiophanate-methyl and its primary metabolite (carbendazim) during oyster mushroom (Pleurotus ostreatus var. florida) cultivation was done for two consecutive years 2017 and 2018. Wheat straw substrate was chemically treated with different treatments of thiophate-methyl, viz, thiophanate-methyl 30 ppm + formalin 500 ppm (T1), thiophanate-methyl 40 ppm + formalin 500 ppm (T2), thiophanate-methyl 50 ppm + formalin 500 ppm (T3), thiophanate-methyl 60 ppm + formalin 500 ppm (T4), and formalin 500 ppm (T5 as control and recommended concentration), and utilized for cultivation of oyster mushroom. Treatments T3 and T4 exhibited significant difference in pH levels during both the trials. Minimum spawn run, pinhead formation, and fruit body formation time were recorded in treatments T3 and T4. Significantly higher biological efficiency (%) was recorded in treatments T3 and T4 as compared with all other treatments. No incidence of competitor molds was recorded in T3 and T4. Pesticide residue analysis for detection of thiophanate-methyl and its metabolite (carbendazim) was done in the fruit body produced in T3 and T4 treatments using liquid chromatography with tandem mass spectrometry method. No residue of thiophanate-methyl and carbendazim was detected at 50 ppm concentration of thiophanate-methyl during both the trials. However, in trial II, residue of carbendazim (5.39 μg/kg) was detected at 60 ppm. Based on the findings of the trials I and II, T3 (thiophanate-methyl 50 ppm + formalin 500 ppm) may be utilized for substrate sterilization for oyster mushroom cultivation and Pleurotus ostreatus var. florida could be recognized as microorganism which could play a role in degradation of thiophanate-methyl.

Agro-residues disinfection methods for mushroom cultivation: A review

Agro residues have effectively been utilized as a substrate in mushroom cultivation. The substrates used in cultivating edible mushroom requires varying degree of pre-treatments in order to promote the growth of mushroom mycelium by excluding other competitor microorganisms. Sterilization using hot water, steam or chemical methods is done to disinfect the substrate. However, sterilization is not an ideal disinfection method as it kills both beneficial and harmful organisms in the substrate. Pasteurisation of the substrate seems to be the better alternative which permits re-growth of beneficial organisms during the cooling period. This paper presents an outline on the utilisation of agro residues as substrate in mushroom cultivation. Various methods of chemical, non-chemical sterilization and pasteurisation of substrate have been discussed. It also highlights that more focus is needed to promote mushroom growers to adopt the pasteurization technique than sterilization by developing simple and low cost pasteurization equipments for rural and small scale mushrooms growers.

Thermophilic solid-state fermentation of rapeseed meal and analysis of microbial community diversity

To reduce the high cost caused by steam sterilization of fermentation substrates and equipments in mesophilic solid-state fermentation of rapeseed meal (RM), a thermophilic protease-producing strain RM-2 from RM was isolated and employed in thermophilic solid-state fermentation of unsterilized RM for polypeptide preparation. The isolate was identified as Geobacillus stearothermophilus by appearance of colonies and microscopic observation as well as 16S rDNA sequencing. The highest yield of polypeptide (9.67%) was obtained by RM-2 at 50% moisture content, 55 °C and 24 h fermentation time. Analysis of microbial community diversity in fermented RM revealed Geobacillus stearothermophilus as dominant strain inhibiting most mesophilic microorganisms. Thermophilic solid-state fermentation on RM improved the yield of rapeseed polypeptide, as well as the utilization rate of substrate. The application of this technology (thermophilic solid-state fermentation) would be environmentally friendlier and energy-saving to industry.

Thin stillage treatment and co-production of bio-commodities through finely tuned Chlorella vulgaris cultivation

Recent years marked the revitalization of microalgal phytoremediation efforts due to the promise of converting organic-rich effluents into various biofuels and biocommodities, including potential CO2 uptake. In this work, the phytoremediation potential and subsequent production of Chlorella vulgaris biomass containing high added-value metabolites were investigated using thin stillage effluent generated by a starch-based ethanol production plant. A fractional-factorial strategy was developed in order to reveal and understand the variables influencing the investigated process, followed by central composite and response surface methodologies for maximizing the desired outputs. Among process variables such as antibiotic addition, substrate sterilization, pH, light regimes and agitation speed, the latter three manifested the strongest effects on the microalgal proliferation and their phytoremediation efficiency. Further insights on desired process conditions were obtained targeting both maximal effluent treatment and microalgal commodities potentials with minimum operating costs. 85% of total carbon and all of the glycerol, organic acids and carbohydrates were consumed by the microalgae under reduced illumination, pH 6 and 290 rpm after 7 d of cultivation. The Chlorella vulgaris biomass was produced at a rate of 0.9 g/L/d manifesting a high protein content of 32% (w/w) together with 14% (w/w) of carbohydrates and 7% (w/w) of lipids. In addition, natural photosynthetic pigments were generated at a rate of 0.98 mg/L/d (total chlorophylls) and 0.19 mg/L/d (carotenoids). This work highlights the potential of a novel microalgae-based thin stillage phytoremediation process with simultaneous co-generation of high added-value metabolites.

Survey of mushroom consumption and the possible use of gamma irradiation for sterilization of compost for its cultivation in Southern Ghana

BackgroundMushroom cultivation is increasingly becoming a serious agribusiness in Ghana, especially at the time when entrepreneurship is being encouraged to reduce the pressure of employment in the government sector and also due to its nutritional and medicinal attributes.MethodsA survey was carried out using the rapid appraisal method to review the existing methods of sterilization, use of gamma radiation in substrate sterilization and food preservation, preference of mushrooms in Ghana by consumers and nutritional and medicinal attributes of the mushroom.ResultsThe survey demonstrated the popularity of drum (moist heat) technique of sterilization in Ghana. Majority (64%) of the respondents were dissatisfied with the method of sterilization of compost and spawn substrate, while 36% indicated the method was alright by them. Majority (82%) of the respondents had never heard of sterilization of substrates for cultivation and its subsequent preservation of food or mushroom by gamma irradiation technique. All consumers (100%) desired to see their favorite mushroom produced all year round, and this constituted a significant (p < 0.05) viewpoint. Furthermore, a significant (p < 0.05) majority (90%) of the respondents were all for promotion of the consumption of mushroom, while a small percentage (10%) were noncommittal.ConclusionInformation and knowledge on the gamma irradiation technique for substrate production and consumption patterns of P.ostreatus mushrooms were not widely disseminated as anticipated.