Research Progress on Auricularia delicata

Aims: To describe the current status of A. delicata emphasizing on the key parameters; occurrence, classification, molecular studies, nutritional and medicinal benefits, cultivation status, and future development perspective. Place and Duration of Study: China–Zambia Agricultural demonstration center and Engineering Research Center of Chinese Ministry of Education for Edible and Medicinal Fungi, Jilin Agricultural University, China between July 2019 and June 2020. Methodology: In this study, various literatures were reviewed for each parameter studied. Findings were deduced from current literatures and discussed. Results: The screening of bioactive contents of A. delicata revealed the presence of phenolic compounds; chlorogenic, flavonoids, and ethyl acetate, polysaccharides; Chitosan, fibers, β-glucans, mannans, chitin, and melanin. These substances exhibit hepatoprotective effects, antioxidant activities and antimicrobial activities against some microbes like Candida albicans, Bacillus subtilis, Enterococcus faecium, Streptococcus aureus, Bacillus cereus, Salmonella typhi and Escherichia coli. A. delicata also contains several nutrients namely; protein, vitamin B2, vitamin C, and minerals; Potassium, Calcium, Iron, Magnesium, Zinc, Manganese, that play a vital role in human growth and development. Moreover, its cultivation using various technologies provides an opportunity for high yield production. A. delicata was recently studied at Jilin Agricultural University and domesticated in Heilongjiang province in the northeastern part of China. Due to the similarity of its fruiting body with the structure of the deer tripe, it was assigned a common name as “Deer tripe mushroom”. A. delicata mycelia are capable of growing on several culture media with different nutritional profiles, optimal temperatures and pH values. It is cultivated under tropic temperatures ranging from 25°C-30°C, optimal pH of 6.5, and humidity 80-90%. The commonly used media include; Potato Dextrose Agar (PDA), Yeast Extract Agar (YEA) and Malt Extract Agar (MEA). Conclusion: Therefore the above mentioned significant properties (occurrence, nutritional, medicinal, and cultivation) provide a foundation for further research on the development and utilization of A. delicata.

Bolbea parasitica gen. et sp. nov., a cultivable holocarpic parasitoid of the early-diverging Saprolegniomycetes

Holocarpic oomycetes convert their entire cytoplasm into zoospores and thus do not form dedicated sporangia or hyphal compartments for asexual reproduction. The majority of holocarpic oomycetes are obligate parasites and parasitoids of a diverse suite of organisms, among them green and red algae, brown seaweeds, diatoms, fungi, oomycetes and invertebrates. Most of them are found among the early diverging oomycetes or the Peronosporomycetes, and some in the early-diverging Saprolegniomycetes (Leptomitales). The obligate parasitism renders it difficult to study some of these organisms. Only a few members of the genus Haliphthoros s. l. have been cultured without their hosts, and of the parasitoid Leptomitales, some transient cultures have been established, which are difficult to maintain. Here, the cultivation of a new holocarpic oomycete genus of the Leptomitales, Bolbea, is presented. Bolbea is parasitic to ostracods, is readily cultivable on malt extract agar, and upon contact with water converts its cytoplasm into zoospores. Its morphology and phylogenetic relationships are reported. Due to the ease of cultivation and the ready triggering of zoospore development, similar to some lagenidiaceous oomycetes, the species could be a promising model to study sporulation processes in detail.

Mycelial growth of the edible wild mushrooms Floccularia luteovirens in different culture mediums and pH

Objectives: To evaluate mycelial growth and biomass production of F. luteovirens in different culture mediums and pH values.Design/methods/approach: The study was carried out in two stages. In the first stage, the amount of biomass produced and growth rate was measured in five generalist culture mediums. During the second stage, the pH was adjusted to 4, 5, and 6 in three of the five mediums, in order to increase biomass and growth speed shown in the first stage.Results: pH is an influential factor in the availability of nutrients needed by the fungus, which is shown by the increase or inhibition of mycelial growth and biomass production. During the first stage, coconut and malt extract agar were the most favorable for mycelial development, while corn meal agar was the least favorable. When the pH was modified, malt extract agar with a pH of 4 was the most efficient in terms of growth rate, while coconut agar demonstrated the most biomass production regardless of pH.Study limitations and implications: The growth of cultures in vitro is slow when compared with other mushrooms species.Findings/Conclusions: Floccularia luteovirens cultivation represents an alternative to obtain food with a high nutritionalvalue, safeguard germplasm, and increase and diversify species cultivated; since it is edible, with high nutritional contentand has medicinal properties.

Toxin Production by Stachybotrys chartarum Genotype S on Different Culture Media

Stachybotrys (S.) chartarum had been linked to severe health problems in humans and animals, which occur after exposure to the toxic secondary metabolites of this mold. S. chartarum had been isolated from different environmental sources, ranging from culinary herbs and improperly stored fodder to damp building materials. To access the pathogenic potential of isolates, it is essential to analyze them under defined conditions that allow for the production of their toxic metabolites. All Stachybotrys species are assumed to produce the immunosuppressive phenylspirodrimanes, but the highly cytotoxic macrocyclic trichothecenes are exclusively generated by the genotype S of S. chartarum. In this study, we have analyzed four genotype S strains initially isolated from three different habitats. We grew them on five commonly used media (malt-extract-agar, glucose-yeast-peptone-agar, potato-dextrose-agar, cellulose-agar, Sabouraud-dextrose-agar) to identify conditions that promote mycotoxin production. Using LC-MS/MS, we have quantified stachybotrylactam and all S-type specific macrocyclic trichothecenes (satratoxin G, H, F, roridin E, L-2, verrucarin J). All five media supported a comparable fungal growth and sporulation at 25 °C in the dark. The highest concentrations of macrocyclic trichothecenes were detected on potato-dextrose-agar or cellulose-agar. Malt-extract-agar let to an intermediate and glucose-yeast-peptone-agar and Sabouraud-dextrose-agar to a poor mycotoxin production. These data demonstrate that the mycotoxin production clearly depends on the composition of the respective medium. Our findings provide a starting point for further studies in order to identify individual components that either support or repress the production of mycotoxins in S. chartarum.

Several Metarhizium Species Produce Ergot Alkaloids in a Condition-Specific Manner

ABSTRACT Genomic sequence data indicate that certain fungi in the genus Metarhizium have the capacity to produce lysergic acid-derived ergot alkaloids, but accumulation of ergot alkaloids in these fungi has not been demonstrated previously. We assayed several Metarhizium species grown under different conditions for accumulation of ergot alkaloids. Isolates of M. brunneum and M. anisopliae accumulated the lysergic acid amides lysergic acid α-hydroxyethyl amide, ergine, and ergonovine on sucrose-yeast extract agar but not on two other tested media. Isolates of six other Metarhizium species did not accumulate ergot alkaloids on sucrose-yeast extract agar. Conidia of M. brunneum lacked detectable ergot alkaloids, and mycelia of this fungus secreted over 80% of their ergot alkaloid yield into the culture medium. Isolates of M. brunneum, M. flavoviride, M. robertsii, M. acridum, and M. anisopliae produced high concentrations of ergot alkaloids in infected larvae of the model insect Galleria mellonella, but larvae infected with M. pingshaense, M. album, M. majus, and M. guizhouense lacked detectable ergot alkaloids. Alkaloid concentrations were significantly higher when insects were alive (as opposed to killed by freezing or gas) at the time of inoculation with M. brunneum. Roots of corn and beans were inoculated with M. brunneum or M. flavoviride and global metabolomic analyses indicated that the inoculated roots were colonized, though no ergot alkaloids were detected. The data demonstrate that several Metarhizium species produce ergot alkaloids of the lysergic acid amide class and that production of ergot alkaloids is tightly regulated and associated with insect colonization. IMPORTANCE Our discovery of ergot alkaloids in fungi of the genus Metarhizium has agricultural and pharmaceutical implications. Ergot alkaloids produced by other fungi in the family Clavicipitaceae accumulate in forage grasses or grain crops; in this context they are considered toxins, though their presence also may deter or kill insect pests. Our data report ergot alkaloids in Metarhizium species and indicate a close association of ergot alkaloid accumulation with insect colonization. The lack of accumulation of alkaloids in spores of the fungi and in plants colonized by the fungi affirms the safety of using Metarhizium species as biocontrol agents. Ergot alkaloids produced by other fungi have been exploited to produce powerful pharmaceuticals. The class of ergot alkaloids discovered in Metarhizium species (lysergic acid amides) and their secretion into the growth medium make Metarhizium species a potential platform for future studies on ergot alkaloid synthesis and modification.

عزل وتعريف واختبار كفاءة بعض الفطريات في تحلل الهيدروكربون من التربة الملوثة بالنفط

استهدفت هذه الدراسة عزل بعض أنواع الفطريات من التربة الملوثة بالهيدروكربون بمصفاة الزاوية لتكرير النفط، حيث تم عزل وتعريف بعض الفطريات مثل Rhizopus, Aspergillus fumigatus, Aspergillus niger, Aspergillus flavus, Aspergillus nidulans وأوضحت نتائج هذه الدراسة أن تواجد وتنوع فطر Aspergillus قد تفوق معنويا مقارنة بتواجد وتنوع فطرRhizopus. كما تم في هذه الدراسة اختبار قدرة وكفاءة الفطريات المعزولة على النمو واستغلال المركبات الهيدروكربونية المتمثلة في زيت الحمادة وزيت الشرارة بتركيز 1% و3%، حيث أوضحت النتائج بأن جنس Rhizopus سجل أعلى معدل للنمو على الوسط الغذائي Malt Extract Agar، وسجل كلا من فطر A. fumigatus وفطر A. flavus معدّل النمو القطري أعلى معنويا من النمو القطري لفطرA. niger وفطر A. nidulans. هذه المعدّلات العالية تدل على إمكانية استخدام الفطريات المعزولة في المعالجة البيولوجية للتربة الملوّثة بالنفط.

Promising entomopathogenic strain of Bacillus thuringiensis 0428 effective against the Colorado beetle

Most of the world produced biopesticides are made by entomopathogenic bacteria B. thuringiensis. So, searching for new strains of it is always necessary. In 2006, the strain B. thuringiensis 0428 was isolated from the caterpillar of the ringed silkworm. The strain 0428 is entomopathogenic against Colorado beetle larvae. The effectiveness of the strain for 5 days was 100%. On beef-extract agar this Gram-positive bacterium formed round or irregular colonies with an average diameter of 6-10 mm. The relief of the colonies is flat; the surface is matte. Colonies of B. thuringiensis 0428 are fast-growing, appearing on the surface of the beef-extract agar on the second or third day at 26-30ºC. The average cell size is 6.48±0.16 (large diameter) and 2.62±0.06 (small diameter) microns. The study of the physiological and biochemical properties of the isolated strain shown that B. thuringiensis 0428 is able to form acetyl-methyl-carbinol and lecithinase. B. thuringiensis 0428 is not able to form ureases or pigments, as well as to use citrates and galactose. But it is able to use sucrose, glucose, mannose, and salicin as a source of carbon. The strain 0428 has proteolytic activity. The strain is capable of synthesizing an insecticidal crystalline protein Cry1A and β-exotoxin. All these characteristics allow us to identify the isolated entomopathogenic strain 0428 as B. thuringiensis var. thuringiensis.

ISOLASI DAN IDENTIFIKASI KAPANG PADA PINDANG BANDENG (Chanos chanos) PRESTO

Ikan pindang adalah salah satu olahan yang sangat disukai oleh masyarakat Indonesia. Hal ini dapat dilihat dari produksi ikan pindang yang setiap tahunnya mengalami peningkatan. Sebagai contoh di Kabupaten Bogor, produksi ikan pindang pada tahun 2013 sebesar 3.643,56 ton, meningkat menjadi 10.334,44ton pada tahun 2015. Ikan pindang disisi lain, sangat mudah mengalami kemunduran mutu disebabkan masih tingginya kadar air, pengemasan yang tidak memenuhi standar serta proses pengolahan yang pada umumnya kurang menerapkan prinsip sanitasi yang baik. Penelitian ini bertujuan untuk mengisolasi dan mengidentifikasi kapang yang tumbuh pada bandeng presto. Sampel Bandeng presto diambil dari CV. Cindy Group. Kapang diisolasi dengan metode pengenceran bertingkat menggunakan media DRBC (Dichloran Rose Bengal Chloramphenicol Agar), kemudian diidentifikasi secara morfologi menggunakan media Malt Extract Agar dan Czapek’s Yeast Extract Agar. Nilai Aktivitas air (aw) bandeng presto memiliki kisaran rata-rata 0,96 – 0,97. Secara makroskopis terlihat adanya pertubuhan kapang pada permukaan ikan bandeng presto setelah penyimpanan selama 3 hari pada suhu ruang (20-250C). Sebanyak 5 isolat kapang diisolasi dari ikan pindang sampel bandeng presto. Hasil identifikasi secara mikroskopis diketahui bahwa kapang yang tumbuh ada ikan pindang tersebut adalah spesies Penicillium citrinum, Eurotium chevalieri, Fusarium solani, Fusarium sp, dan Cladosporium sp. Kadar aw ikan pindang resto yang masih tinggi (0,96-0,97) menyebabkan ikan pindang mengalami pembusukan yang diakibatkan oleh bakteri.