Influence of wheat cultivars on straw quality and Pleurotus ostreatus cultivation

The main raw material for Pleurotus ostreatus (oyster mushroom) cultivation is wheat straw. Estimation of straw biodegradability from 15 different spring wheat cultivars under irrigation in South Africa was determined using linear discriminant analysis to discriminate or group the 15 cultivars by combining chemical analysis and in vitro enzymatic hydrolysis. Significant differences (P < 0.01) were found between ash, nitrogen, reducing sugars, anthrone reactive-carbohydrates, water-soluble dry matter, and oyster mushroom yields. The significance of these measurements was investigated and discussed.     

An airborne actinobacteria Nocardiopsis alba isolated from bioaerosol of a mushroom compost facility

Actinobacteria are widely distributed in many environments and represent the most important trigger to the occupant respiratory health. Health complaints, including hypersensitivity pneumonitis of the workers, were recorded in a mushroom compost facility (MCF). The studies on the airborne bacteria were carried out to find a possible microbiological source of these symptoms. Culture analysis of compost bioaerosols collected in different location of the MCF was performed. An assessment of the indoor microbial exposure revealed bacterial flora of bioaerosol in the mushroom compost facility represented by Bacillus, Geobacillus, Micrococcus, Pseudomonas, Staphylococcus spp., and actinobacterial strain with white aerial mycelium. The thermotolerant actinobacterial strain of the same morphology was repeatedly isolated from many locations in MCF: air, compost sample, and solid surface in production hall. On the base of complex morphological, chemotaxonomic, and phylogenetic characteristics, the isolate has been classified as Nocardiopsis alba. Dominant position of N. alba in microbial environment of the mushroom compost facility may represent an indicator microorganism in compost bioaerosol. The bioavailability of N. alba in mushroom compost facility creates potential risk for the health of workers, and the protection of respiratory tract and/or skin is strongly recommended.     

Solid state fermentation of Saccharum munja residues into food through Pleurotus cultivation

The technical feasibility of using Saccharum munja as a substrate for the cultivation of the oyster mushroom, Pleurotus sajor-caju, is evaluated. The biological efficiency of mushroom production is compared on different substances-S. munja, S. munja plus paddy straw, and paddy straw. Although the efficiency is low on S. munja, the ready availability of this weed large areas holds a favourable option for its use in mushroom cultivation. The crude proteins, fats, carbohydrates, and energy values are also lower though the differences are not great. The degradation of three major components-cellulose, hemicellulose, and lignin has been observed, which proves P. sajor-caju to be a lignocellulolytic fungus. The nitrogen and mineral analysis of post-mushroom production S. munja (spent substrate) compares favorably with the dry cow-feed ration showing an enhanced protein content in the spent substrate.     

Impact of the natural resource of UVB on the content of vitamin D2 in oyster mushroom (Pleurotus ostreatus) under subtropical settings

Vitamin D deficiency is a pandemic problem. Non-animal source of vitamin D is obtained from edible mushrooms. Oyster mushroom (Pleurotus ostreatus) was sliced into the size of 1 cm³, 4 cm³ and 9 cm³, and treated with the sun as a natural resource of UVB under subtropical settings in Ethiopia. The content of vitamin D was measured by using high-performance liquid chromatography (HPLC). After sun treatment, there was a significant increment in the content of vitamin D₂ from nil to 67.4 ± 28.0 µg/g dry weight (DW). Based on the results of the overall pairwise comparisons, 1 cm³ size of slice group had the highest content of vitamin D₂. Duration of sun exposure, sizes of mushroom slices and moisture content were identified as determining factors for vitamin D₂ synthesis. Exposing slices of oyster mushroom to the sunlight for <30 min provides the amount that satisfies the current recommended dietary allowance (RDA) of vitamin D without any visible change in color and texture. Thus, sun treatment of oyster mushroom is an effective and economically cheap strategy in the fight against vitamin D deficiency.     

β-cyclodextrin production by the cyclodextrin glucanotransferase from Paenibacillus illinoisensis ZY-08: cloning, purification, and properties

The gene encoding the cyclodextrin glucanotransferase (CGTase, EC2.4.1.19) of Paenibacillus illinoisensis was isolated, cloned, sequenced and expressed in Escherichia coli. Sequence analysis showed that the mature enzyme (684 amino acids) was preceded by a signal peptide of 34-residues. The deduced amino acid sequence of the CGTase from P. illinoisensis ZY-08 exhibited highest identity (99 %) to the CGTase sequence from Bacillus licheniformis (P14014). The four consensus regions of carbohydrate converting domain and Ca²⁺ binding domain could be identified in the sequence. The CGTase was purified by using cold expression vector, pCold I, and His-tag affinity chromatography. The molecular weight of the purified enzyme was about 74 kDa. The optimum temperature and pH of the enzyme were 40 °C and pH 7.4, respectively. The enzyme activity was increased by the addition of Ca²⁺ and inhibited by Ba²⁺, Cu²⁺, and Hg²⁺. The K _m and V _max values calculated were 0.48 mg/ml and 51.38 mg of β-cyclodextrin/ml/min. The ZY-08 and recombinant readily converted soluble starch to β-cyclodextrin but ZY-08 did not convert king oyster mushroom powder and enoki mushroom powder. However the recombinant CGTase converted king oyster mushroom powder and enoki mushroom powder to β-cyclodextrin.     

Yellow Blotch of Pleurotus ostreatus

Yellow blotch disease of the oyster mushroom (Pleurotus ostreatus) was first observed in a commercial mushroom farm in California in 1983. The disease, caused by Pseudomonas agarici, is characterized by primordia, with yellow droplets on their surface, which become stunted, yellow to orange, and deformed as they mature.     

The composition of volatile components of dry cepe and oyster mushroom

The composition of aroma compounds in dry cepe mushroom (Boletis edulis Fr.) and oyster mushroom (Pleurotus ostreatus Fr.) was studied using capillary gas chromatography and chromatography—mass spectrometry. In dry cepe, 53 volatile compounds were identified, and in dry oyster mushroom 41 compounds were identified. Volatile organic substances with various functional groups formed the flavor of dry mushrooms. Unsaturated alcohols and ketones with eight carbon atoms were responsible for the mushroom notes of products. Their content in dry cepe was much higher than in dry oyster mushroom. The specific aroma of dry cepe was formed by the complex mixture of methional, substituted furans, pyrazines, and pyrroles. The content of these compounds was higher in dry cepe than in dry oyster mushroom. The content of aromatic and aliphatic aldehydes with six, nine, and ten carbon atoms was higher in dry oyster mushroom. The differences in the qualitative and quantitative composition of volatile compounds are responsible for more intensive and pleasant aroma of dry cepe in comparison to that of dry oyster mushroom.     

Influence of Ficus carica and Olea europaea leaves extracts on the mycelial growth of mushrooms in vitro

The use of 20% plant leaves extracts included fig (Ficus carica) and olive (Olea europaea) and their mixture 1:1 as an amendment in the solid agar medium (PDA) is beneficial to promote the growth of four mycelial mushrooms. These are Pleurotus ostreatus (Grey oyster mushroom), Pleurotus cornucopiae (Yellow oyster mushroom), Coriolus versicolor (Turkey Tail mushroom), and Ganoderma lucidum (Reishi mushroom). C. versicolor showed better growth reached 67?mm significantly (p?<?0.05) on OC medium after five days. While, P. cornucopiae recorded the lowest growth on FC medium reached 35.3?mm. Induction percentage of mycelial growth is changing according to the type of medium and species of fungus. In general, FOH medium exhibited the best percentage of induction was 14.89%, followed 12.48% and 9.43% by OH and OC media, while the lower percentages were 5.02% and 5.12% on FH and FC media, respectively. FC medium did not induce growth of P. cornucopiae and C. versicolor. The sterilization by Autoclave and Millipore filter showed different induction percentages. Finally, the extracts of fig and olive were useful to add in the culture media to improve the growth of mycelial mushroom in vitro.     

Comparative study on the growth and yield of<Emphasis Type="Italic"> Pleurotus ostreatus</Emphasis> mushroom on different lignocellulosic by-products

Eight lignocellulosic by-products were evaluated as substrates for cultivation of the oyster mushroom, Pleurotus ostreatus (Jacq. ex. fr) Kummer. The yields of mushroom on the different substrates were 183.1, 151.8, 111.5, 87.8, 49.5, 23.3, 13.0 and 0.0 g for composted sawdust of Triplochiton scleroxylon, rice straw, banana leaves, maize stover, corn husk, rice husk, fresh sawdust, and elephant grass, respectively. The biological efficiency (BE) followed the same pattern and ranged from 61.0% for composted sawdust to 0.0% for elephant grass. The yield of mushroom was positively correlated to cellulose (r ² =0.6), lignin (r ² =0.7) and fibre (r ² =0.7) contents of the substrates. Based on the yield and BE of the substrates tested, rice straw appeared to be the best alternate substrate for growing oyster mushrooms. Electronic Publication     

Yield,size, nutritional value,and antioxidant activity of oyster mushrooms grown on perilla stalks

Perilla is an edible medical plant with rapidly increasing acreage in China. In this study, we investigated the potential of perilla stalks (PSs) as an alternative substrate for the cultivation of oyster mushrooms (Pleurotus ostreatus). P. ostreatus was cultivated on cottonseed hulls (CSH) alone or mixed with PSs in different ratios. The production parameters, physical characteristics, nutritional values, and antioxidant activity of mushrooms cultivated on different substrate mixtures were determined. The addition of PSs to CSH significantly improved the growth rate, yield, biological efficiency, and proximate composition and shortened the cultivation cycle. Cultivation on PSs alone increased the amino acid content in P. ostreatus fruiting bodies and the antioxidant activity of mushroom extracts. The PS75 (25% CSH + 75% PS) substrate was deduced to be the most effective substrate on the basis of yield and biological efficiency obtained in a large area where perilla had been planted. The results demonstrate that mixtures of PS with CSHs could be used as novel, practical, and easily accessible alternative substrates for P. ostreatus cultivation.     

Use of extracts from oyster shell and soil for cultivation of Spirulina maxima

Calcium ion and trace metals play important roles in various metabolisms of photosynthetic organisms. In this study, simple methods were developed to extract calcium ion and micronutrients from oyster shell and common soil, and the prepared extracts were tested as a replacement of the corresponding chemicals that are essential for growth of microalgae. The oyster shell and soil were treated with 0.1 M sodium hydroxide or with 10 % hydrogen peroxide, respectively. The potential application of these natural sources to cultivation was investigated with Spirulina maxima. When compared to standard Zarrouk medium, the Spirulina maxima cultivated in a modified Zarrouk media with elements from oyster shell and soil extract exhibited increases in biomass, chlorophyll, and phycocyanin by 17, 16, and 64 %, respectively. These results indicate that the extracts of oyster shell and soil provide sufficient amounts of calcium and trace metals for successful cultivation of Spirulina maxima.     

Dedikaryotization of higher fungi in submerged culture

Shaker experiments were done with submerged propagation of the oyster pleurotus (Pleurotus ostreatus/Jacq. ex. Fr./Kummer). The starting material was dikaryotic or monokaryotic mycelium obtained under stationary conditions. During submerged cultivation in a wort-containing medium on a cyclic shaker at 240 r.p.m. in flasks with articulated surface, dedikaryotization took place and the culture was predominantly monokaryotic after 10–14 days. Agitation of the medium favours the formation of monokaryotic forms. The typical mushroom flavour is associated with the dikaryotic form of mycelium so that submerged cultivation does not produce higher fungal mycelium in its aromatic form.     

Cultivation of different strains of king oyster mushroom (Pleurotus eryngii) on saw dust and rice straw in Bangladesh

Pleurotus eryngii is a popular mushroom due to its excellent consistency of cap and stem, culinary qualities and longer shelf life. In Bangladesh, where Pleurotus mushrooms are very popular, P. eryngii may take position among the consumers, but currently this mushroom is not cultivated in large scale there. In this study, 3 strains of P. eryngii such as Pe-1 (native to Bangladesh), Pe-2 (germplasm collected from China) and Pe-3 (germplasm collected from Japan) were cultivated on saw dust and rice straw and their growth and yield parameters were investigated. Pe-1 on saw dust showed the highest biological yield and efficiency (73.5%) than other strains. Also, the mycelium run rate and number of fruiting bodies were higher in Pe-1 than other two strains. The quality of mushroom strains was near about similar. On saw dust, the yield and efficiency were better than those cultivated on rice straw, however, on straw; the mushroom fruiting bodies were larger in size. This study shows the prospects of P. eryngii cultivation in Bangladesh and suggests further study in controlled environment for higher yield and production.     

Diversity of Trichoderma spp. causing Pleurotus green mould diseases in Central Europe

The present study includes the molecular characteristics of Trichoderma pleurotum and Trichoderma pleuroticola isolates collected from green moulded cereal straw substrates at 47 oyster mushroom farms in Poland. The screening of the 80 Trichoderma isolates was performed by morphological observation and by using the multiplex PCR assay. This approach enabled specific detection of 47 strains of T. pleurotum and 2 strains of T. pleuroticola. Initial identifications were confirmed by sequencing the fragment of internal transcribed spacer regions 1 and 2 (ITS1 and ITS2) of the rRNA gene cluster and the fragment including the fourth and fifth introns and the last long exon of the translation–elongation factor 1-alpha (tef1) gene. ITS and tef1 sequence information was also used to establish the intra- and interspecies relationship of T. pleurotum and T. pleuroticola originating from the oyster mushroom farms in Poland and from other countries. Comparative analysis of the ITS sequences showed that all T. pleurotum isolates from Poland represent one haplotype, identical to that of T. pleurotum strains from Hungary and Romania. Sequence analysis of the tef1 locus revealed two haplotypes (“T” and “N”) of Polish T. pleurotum isolates. The “T” type isolates of T. pleurotum were identical to those of strains from Hungary and Romania. The “N” type isolates possessed a unique tef1 allele. Detailed analysis of the ITS and tef1 sequences of two T. pleuroticola isolates showed their identicalness to Italian strain C.P.K. 1540.     

3种不同来源侧耳品种亲缘关系差异化分析

采取拮抗实验、酯酶同工酶、基因组进行多态性分析(RAPD)、内部转录间隔区序列(ITS)对来源不同的特大凤尾菇(Pleurotus sajor-caju)、夏秀990(Pleurotus geesteranus)和黑平A3三个侧耳品种的亲缘关系进行了对比分析。实验结果表明:供试的3个侧耳品种从形态学水平、蛋白质水平和分子水平上看,其品种间亲缘关系界定具有一致性。表现为特大凤尾菇与夏秀990的亲缘关系较近,与黑平A3的亲缘关系较远,夏秀990与黑平A3亲缘关系较远。本研究从不同的水平,为食用菌菌种属间亲缘关系的鉴定提供了综合分析方法,对区分同种异名、杂交亲本选择以及判定杂交结果具有指导意义。     

Cultivation of Pleurotus ostreatus on weed plants

Oyster mushroom, Pleurotus ostreatus (Jacq.:Fr.) Kumm. ITCC 3308 (collected from Indian Type Culture Collection, IARI, New Delhi, India, 110012) was grown on dry weed plants, Leonotis sp, Sida acuta, Parthenium argentatum, Ageratum conyzoides, Cassia sophera, Tephrosia purpurea and Lantana camara. Leonotis sp. was the best substrate in fruit body production of P. ostreatus when it was mixed with rice straw (1:1, wet wt/wet wt) for mushroom cultivation. The fruiting time for P. ostreatus was also less on Leonotis sp. than on any other weed substrates tested in the present investigation. T. purpurea was the least suited weed for oyster mushroom cultivation. The main problem of oyster mushroom cultivation on weed substrates was found to be low yield in the second flush that could be overcome by blending weed plants with rice straw. The protein contents of the fruit bodies obtained from Cassia sophera, Parthenium argentatum and Leonotis sp. were not only better than rice straw but also from the rice straw supplemented weeds.     

Fungal interaction between Trichoderma spp. and Pleurotus ostreatus on the enriched solid media with licorice Glycyrrhiza glabra root extract

The aim of this study is to investigate the antifungal activity of mycelia of Pleurotus ostreatus (white oyster mushroom) and licorice (Glycyrrhiza glabra) root extract against three undesirable fungi. They are Trichoderma spp., Trichoderma harzianum I and Trichoderma harzianum II which was tested on PSA (potato sucrose agar) medium enriched with licorice (Glycyrrhiza glabra) root extract (PSA-G media) using three concentrations (0.05, 0.10 and 0.20 g/L) in alone and dual cultures. Trichoderma spp. showed less mycelial growth of 8.75, 9.17 and 9.50 mm/day on PSA-G0.05, PSA-G0.1 and PSA-G0.2 respectively compared with 10.25 mm/day on fresh PSA (control) in dual culture. The best mycelial growth inhibition was recorded on PSA-G0.2 (14.97%) by T. harzianum II in alone culture opposite 63.72% in dual ones. The lower mycelial growth rate of T. harzianum I was 17.75 mm/day on PSA-G0.1 (0.10 g/L). In dual culture, overgrowth time of T. harzianum I had 5 days compared as approx. 6 days in alone culture. Generally, when the concentration of licorice extract increased, the mycelial growth rate of the undesirable fungi decreased. Also, all PSA-G media, especially PSA-G0.2, indicated low growth averages compared with the control (fresh PSA) against the pathogen while this concentration encourages growth of oyster mushroom. Also, this concentration reduced the density of sporulation of green molds; therefore, this concentration can be applied to reduce influence this pathogen in cultivation farm.     

气候变化对鄱阳湖白鹤越冬种群数量变化的影响

分析了1983—2011年鄱阳湖国家级自然保护区越冬白鹤种群数量的年际变化趋势,检验了白鹤种群动态与繁殖地和越冬地气候变化的相关性,气候变量包括月平均气温、月平均最高气温、月平均最低气温和月降水量。研究结果表明,鄱阳湖国家级自然保护区内的白鹤年最大数量平均为(2 130±153)只,呈显著地线性增长趋势(R2=0.454,F=22.441,df=28,P=0.000),但年际波动较大。在越冬地,越冬当年10月、11月、12月的气候变量与白鹤种群数量没有显著的相关性,但越冬初期10月份和越冬后期翌年3月份的气温变量与第4年、第5年、第6年及第7年的白鹤种群数量存在显著的正相关,表明越冬地气候对白鹤种群大小的影响存在时滞效应。越冬初期和末期可能是白鹤补充能量的关键阶段,而且越冬初期的气候可能也与冬季食物的数量或质量相关,因此这两个阶段的适宜气温可能有利于个体尤其是幼鹤的存活,使更多的个体参加繁殖,由于白鹤的性成熟年龄在3—5a,因此其对白鹤种群增长的有利影响会在3a以后表现出来。白鹤种群数量变化与繁殖地繁殖期的降水量没有显著的相关性,而与7月份的气温变量存在显著的正相关。多元线性回归分析结果表明,6a前的10月份平均最低温度、2a前的10月最高温度及5a前的10月平均气温是白鹤种群数量变化的显著预测因子,共同解释了鄱阳湖国家级自然保护区白鹤种群数量变化的74.8%(F=23.807,df=27,P=0.000)。     

合浦珠母贝鳃的显微与超微结构

合浦珠母贝(Pinctada fucata)是典型的滤食性瓣鳃类动物,也是我国重要的海水珍珠养殖贝类。本研究用光学显微镜、扫描电镜和透射电镜观察了合浦珠母贝鳃的显微和超微结构。结果表明,合浦珠母贝鳃结构属于异丝鳃型,左右两侧各2个鳃瓣,每个鳃瓣由内鳃瓣和外鳃瓣组成。鳃瓣由主鳃丝和普通鳃丝构成,主鳃丝在鳃瓣中主要起支架作用,每2根主鳃丝之间的9～12根普通鳃丝由"簇内连接"(intrabunchial junction)相连成簇。普通鳃丝之间通过"丝间连接"(interfilament junction)相连,丝间连接的上皮细胞与普通鳃丝的扁平细胞结构一样,为鳃的呼吸上皮。丝间连接的存在扩大了鳃的表面积,这种结构有助于进行气体交换。主鳃丝和普通鳃丝表面有前纤毛和侧纤毛,与食物运送和气体交换有关。普通鳃丝表面的纤毛为典型的"9+2"型微管结构。