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.

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.

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.

Prevalence of spoilage mold in coffee before and after brewing

Commercial ground coffee must be safe for consumption and comply with the regulation applied in a country. However, the risk of the occurrence of spoilage molds in commercial ground coffee, particularly toxigenic mold originated from coffee cherries or green beans, is still a major concern of the coffee industry. This study evaluated the prevalence of spoilage mold in fifteen brands of commercial ground coffee. The spoilage molds were also determined after traditional brewing (non-filtration brewing). The mold counts were enumerated on dichloran-glycerol 18% agar by spread plate method. The spoilage molds were also morphologically identified after isolation on malt extract agar and potato dextrose agar. The results showed that low numbers of molds were found in all samples before brewing, in a range of 10 to 200 CFU/g. A total of eleven genera were identified. Aspergillus, Cladosporium and Penicillium were found as the predominating genera. After brewing, molds from genera Alternaria and Aspergillus were still found. However, the total counts decreased to the level between undetected to an average of 3 CFU/mL. This study highlighted that very low levels of spoilage mold was recovered after brewing which may not pose a health risk.

SKRINING KAPANG Aspergillus spp. PENGHASIL AFLATOKSIN PADA JAGUNG PIPILAN DI DAERAH BEKASI, JAWA BARAT

AbstrakAflatoksin merupakan senyawa metabolit sekunder dari kapang Aspergillus flavus dan Aspergillus parasiticus yang dapat mengontaminasi bahan pangan atau pakan sehingga berbahaya bagi kesehatan hewan dan manusia. Kontaminasi kapang penghasil aflatoksin banyak ditemukan pada bahan pangan dan pakan yang berasal dari produk pertanian. Jagung merupakan salah satu produk pertanian yang mudah terkontaminasi oleh kapang penghasil aflatoksin. Penelitian ini bertujuan untuk memperoleh isolat kapang Aspergillus spp. penghasil aflatoksin pada jagung pipilan yang dijual di sekitar Bekasi, Jawa Barat. Isolasi kapang dilakukan menggunakan metode dilution plating pada medium Dichloran-Glycerol. Hasil penelitian memperoleh 12 isolat kapang, dengan warna koloni hijau (J1, J2, J3, J4, J5, J6, J7, J9, J10, J12), hitam (J11), dan jingga (J8). Identifikasi dilakukan dengan cara mengamati morfologi kapang secara makroskopik dan mikroskopik pada medium Malt Extract Agar. Isolat kapang yang diduga memiliki kemiripan dengan A. flavus berjumlah 6 isolat, yaitu J1, J2, J4, J6, J10, dan J12. Selanjutnya dilakukan uji konfirmasi menggunakan medium selektif Aspergillus flavus dan parasiticus Agar. Terdapat 2 isolat kapang, yaitu J1 dan J4, yang menunjukkan pigmentasi sebalik koloni berwarna pada medium selektif AFPA. Isolat kapang yang ditemukan pada jagung pipilan diharapkan dapat memberikan informasi kepada petani dan peternak mengenai jenis kapang yang dapat menyebabkan kontaminasi pada jagung, sehingga mereka dapat menjaga dan meningkatkan kualitas jagung untuk mengurangi kerugian dalam bidang ekonomi dan kesehatan.Abstract Aflatoxin is a secondary metabolite secreted by the mold Aspergillus flavus and Aspergillus parasiticus that may contaminate food or feed so harmful to human and animal health. Contamination of aflatoxin-producing mold is commonly found in food and feed which derived from agricultural products. Corn is one of the agricultural products that are easily contaminated by aflatoxin-producing mold. The study aims to isolate the aflatoxin-producing mold Aspergillus spp. in stripped corn vend around Bekasi, West Java. The isolation was conducted by using the method of dilution plating on Dichloran-Glycerol medium. The study obtained 12 isolates of mold, with green colony color (J1, J2, J3, J4, J5, J6, J7, J9, J10, J12), black (J11), and jingga (J8). Identification was conducted by observing the morphology of mold on Malt Extract Agar macroscopically and microscopically. The isolates that allegedly have similarities to A. flavus are J1, J2, J4, J6, J10, and J12. Furthermore, a confirmatory test was preceed by using a selective medium of Aspergillus flavus and parasiticus agar. There are 2 isolates of molds, J1 and J4, which showed yellowish jingga pigmentation like the positive control of A. flavus. The isolates of mold found in the stripped corn may provide information to farmers and breeders about the type of mold that can cause contamination in corn, so that they can anticipate in advance and improve the quality of the corn to reduce losses in economic and health perspectives.

Production of hybrid strains among Pleutorus and Lentinula and evaluation of their mycelial growth kinetics on malt extract agar and wheat grain using the Gompertz and Hill models

Three inter-generic hybrid strains were obtained by pairing compatible neohaplonts recovered by dedikaryotization of four parental strains, i.e. Pleurotus ostreatus (CC060), Pleurotus djamor (CC051) and Lentinula edodes (CC003 and CC004). Fifteen neohaplonts were recovered employing homogenization time periods for Pleurotus spp. since 60 to 90 s, and for Lentinula edodes strains time periods ranged from 5 to 20 s, and incubation at 28 °C in a peptone-glucose solution (PGS). The mycelial growth of the parental and hybrid strains was determined on malt extract agar (MEA) and wheat grain by calculating the parameters A, B and C of nonlinear regression models. For the parameter A, the mycelial growth on MEA showed values ranged from 1.08 to 1.28, and for the parameter B since 5.65 to 20.85. On the other hand, the A values by mycelium growth on wheat grain ranged from 1.57 to 16.13, for B since 28.36 to 86.53 and for C were in an interval from 11.89 to 44.24. Parental and hybrid strains presented instantaneous velocity values on MEA since 2.88 to 7.26 cm2•day-1, whereas on wheat grain were in an interval from 5.45 to 10.05 cm3•day-1. Furthemore, the µmax values on MEA and wheat grain were calculated by using the Gompertz model and the λ values on both medium were estimated by using the Hill model, the µmax values on MEA ranged from 0.26 to 1.69 day-1 and λ values in an interval from 0.41 to 2.74, whereas the µmax values on wheat grain ranged from 0.05 to 0.43 day-1 and λ since 1.82 to 28 h. Moreover, the estimated equations based on nonlinear models were used to calculate the µmax values on MEA and wheat grain of the strains and the λ values were obtained by using the µmax values of the proposed equations on the Hill model, the µmax values on MEA ranged from 0.44 to 1.27 day-1 and the λ values between 0.57 to 1.72 h, while the µmax values on wheat grain ranged from 0.04 to 0.64 day-1 and λ values in an interval from 1.26 to 20.11 h. The results evidenced that the hybrid strains of PleurotusxLentinula presented highest rate of growth in comparison with the parental, encouraging the production of hybrid strain and their use in the industrial field.

Ocena in vitro aktywności przeciwgrzybowej niektórych suszonych przypraw ziołowych

W pracy oceniono skład chemiczny oraz aktywność przeciwgrzybową suszonych ziół przyprawowych – bazylii, oregano, rozmarynu i tymianku. Susze zakupiono w sieci handlowej w opakowaniach jednostkowych. W wymieszanym i rozdrobnionym materiale oznaczono zawartość: suchej masy, białka ogółem, cukrów ogółem, polifenoli ogółem i olejków eterycznych. Do oceny aktywności przeciwgrzybowej użyto 12 szczepów grzybów: Alternaria alternata., Aspergillus flavus, A. fumigatus, A. niger, Cladosporium herbarum, Fusarium oxysporum, Penicillium cyclopium oraz Eurotium amstelodami, E. chevalieri, E. herbariorum, E. repens, E. rubrum. W przypadku grzybów z rodzaju Eurotium stosowano podłoże Agar DG18, a w pozostałych – Malt Extract Agar. Na podłożach zawierających dodatek suszu (1 %) prowadzono doświadczalne hodowle grzybów, a na podłożach bez suszu – hodowle kontrolne. Próbę kontrolną pozytywną stanowił benzoesan sodu (0,05 %). W 3. 6. i 9. dobie inkubacji mierzono średnice kolonii doświadczalnych oraz kontrolnych i obliczano procentową inhibicję wzrostu grzybów powodowaną przez susze. Stwierdzono, że aktywność przeciwgrzybowa była zróżnicowana w zależności od rodzaju suszu, gatunku grzyba i czasu inkubacji. W 9. dniu doświadczenia susz z oregano odznaczający się największą zawartością olejku (2,40 % s.m.) i dużą zawartością polifenoli (4,06 % s.m.) powodował istotnie największe średnie zahamowanie wzrostu zarówno grzybów Eurotium ssp. (95,5 %), jak i pozostałych grzybów (90,2 %). Susz bazyliowy o najmniejszej zawartości olejku i polifenoli, a największej – białka ogółem stymulował wzrost części grzybów. Badane susze powodowały największe zahamowanie wzrostu kolonii A. fumigatus, A. alternata i E. amstelodami, a najmniejsze – A. niger i E. rubrum. Hamowanie wzrostu grzybów malało wraz z czasem inkubacji, ale różnice między średnim zahamowaniem wzrostu grzybów w 6. i 9. dniu hodowli były nieistotne. Susze z oregano, tymianku i rozmarynu efektywniej hamowały wzrost kolonii grzybów niż benzoesan sodu.