KARAKTERISTIK PERTUMBUHAN MISELIUM JAMUR TIRAM PUTIH (Pleurotus ostreatus) PADA MEDIUM DASAR JERAMI DAN TONGKOL JAGUNG

Laju pertumbuhan miselium jamur tiram putih (Pleurotus ostreatus (Jacq) P. Kumm) dengan medium dasar jerami dan tongkol jagung telah dilaksanakan di Laboratorium Mikrobiologi Jurusan Biologi Fakultas Matematika dan Ilmu Pengetahuan Alam. Tujuan Penelitian; (a) Untuk mengamati pertumbuhan jamur tiram putih (Pleurotus ostreatus) pada formulasi media limbah jerami dan tongkol jagung; (b) Untuk mengetahui perbandingan dosis limbah jerami dan tongkol jagung yang dapat memberikan pertumbuhan terbaik terhadap jamur tiram putih. Penelitian ini didesain berdasarkan Rancangan Acak Lengkap (RAL) yang terdiri dari 7 perlakuan dan 3 kali ulangan. Susunan perlakuan merupakan perbandingan antara Serbuk jerami jagung : serbuk Tongkol Jagung yakni P1 (Serbuk Jerami 100%, tanpa Serbuk Tongkol Jagung), P2 (80% + 20%), P3 (60% + 40%), P4 (40% + 60%), P5 (20% + 80%), P6 (Serbuk Tongkol Jagung 100%, tanpa Serbuk jerami), P7 (Serbuk Gergaji 70% + Dedak Padi 20% + Tepung Jagung 10%, tanpa Serbuk Jerami dan Tongkol Jagung). Parameter pengamatan; (a) Media dasar pertumbuhan; (b) Karakteristik mikroskopik hifa; (c) Laju pertumbuhan miselium; (d) Karakteristik makroskopik koloni; (e) Masa inkubasi. Hasil penelitian menunjukkan laju pertumbuhan miselium tercepat pada perlakuan P4 yaitu 103 mm dan terendah pada perlakuan P1 yaitu 75 mm. Jumlah koloni (CFU) tertinggi pada perlakuan P7 yaitu 1,6x1012CFU/g dan terendah pada perlakuan P4 yaitu 0,2x1012CFU/g. Waktu inkubasi paling cepat pada perlakuan P7 yaitu 28 hari dan terendah pada perlakuan P4 yaitu 30 hari.

POTENSI EKONOMI LIMBAH TANDAN KOSONG KELAPA SAWIT DAN DEDAK PADI SEBAGAI MEDIA TUMBUH MISELIUM JAMUR TIRAM PUTIH (Pleurotus ostreatus)

Penelitian ini perlu di lakukan karena pada limbah tandan kosong kelapa sawit dan dedak padi merupakan sumber nutrisi yang bernilai ekonomi tinggi yang dapat dimanfaatkan sebagai media pertumbuhan jamur tiram putih (Pleurotus ostreatus). Tujuan penelitian ini adalah (1) mengetahui pertumbuhan miselium jamur tiram putih (P. ostreatus) pada substrat limbah tandan kosong kelapa sawit dan dedak padi; (2) mengetahui karakteristik pertumbuhan jamur tiram putih (P. ostreatus) pada perlakuan jenis substrat yang berbeda. Penelitian ini telah di lakukan dalam rancangan acak lengkap (RAL) yang terdiri tujuh perlakuan dan tiga kali pengulangan. Susunan perlakuan merupakan perbandingan antara tandan kosong kelapa sawit : dedak padi, yakni P1 (50% : 50%), P2 (45% : 55%), P3 (40% : 60%), P4 (35% : 65%). P5 (30% : 70%), P6 (25% : 75%), P7 (serbuk geragaji 70%, dedak padi 20%, tepung jagung 10%). Adapun hasil penelitian menunjukkan laju pertumbuhan miselium tercepat pada perlakuan P1 yaitu 89 mm dan terendah pada perlakuan P5 yaitu 80 mm. Jumlah koloni tertinggi pada perlakuan P5 yaitu 1,4x1012 CFU/g dan terendah pada perlakuan P4 yaitu 0,4x1012 CFU/g. Waktu inkubasi paling cepat pada perlakuan P4 yaitu 28 hari dan terendah pada perlakuan P7 yaitu 33 hari.

Fungi anaesthesia

Electrical activity of fungus Pleurotus ostreatus is characterised by slow (h) irregular waves of baseline potential drift and fast (min) action potential likes spikes of the electrical potential. An exposure of the myceliated substrate to a chloroform vapour lead to several fold decrease of the baseline potential waves and increase of their duration. The chloroform vapour also causes either complete cessation of spiking activity or substantial reduction of the spiking frequency. Removal of the chloroform vapour from the growth containers leads to a gradual restoration of the mycelium electrical activity.

Biological parameters and host preference of Tyrophagus putrescentiae (Schrank) on different Pleurotus ostreatus cultivars

Tyrophagus putrescentiae (Acari: Acaridae) is a destructive pest of edible fungi. Different species of edible fungi have variable effects on the growth, development and fecundity of T. putrescentiae, but it is unclear whether these effects exist in the same species. We used nine cultivars of the oyster mushroom (Pleurotus ostreatus) to evaluate the development and reproduction parameters of T. putrescentiae at 26 ± 1°C and 80 ± 5% humidity. Different P. ostreatus cultivars had significant effects on the immature stages, female fertility, and reproductive lifespan. Total egg-to-adult development time ranged from 10.0 ± 1.2 d (on Po389 cultivar) to 12.5 ± 1.0 d (on Po62 cultivar). Mite mortality ranged from 54.3 ± 4.2% (on Po86 cultivar) to 100.0 ± 0.0% (on Po62 cultivar). The number of eggs laid per female ranged from 3.2 ± 0.4 (on Po45 cultivar) to 9.1 ± 1.1 (on Po86 cultivar). The average lifespan of females ranged from 3.0 ± 0.5 d (on Po45 cultivar) to 16.3 ± 1.7 d (on Po86 cultivar). Host preference of the mite was significantly different among the nine cultivars with a preference for cultivars Po65, Po80, Po389, and Po86. These results indicate that P. ostreatus cultivars significantly affect the biology of T. putrescentiae and the relationship between mite damage and mushroom yield.

Genome-wide identification and expression analyses of C2H2 zinc finger transcription factors in Pleurotus ostreatus

The C2H2-type zinc finger proteins (C2H2-ZFPs) regulate various developmental processes and abiotic stress responses in eukaryotes. Yet, a comprehensive analysis of these transcription factors which could be used to find candidate genes related to the control the development and abiotic stress tolerance has not been performed in Pleurotus ostreatus. To fill this knowledge gap, 18 C2H2-ZFs were identified in the P. ostreatus genome. Phylogenetic analysis indicated that these proteins have dissimilar amino acid sequences. In addition, these proteins had variable protein characteristics, gene intron-exon structures, and motif compositions. The expression patterns of PoC2H2-ZFs in mycelia, primordia, and young and mature fruiting bodies were investigated using qRT-PCR. The expression of some PoC2H2-ZFs is regulated by auxin and cytokinin. Moreover, members of PoC2H2-ZFs expression levels are changed dramatically under heat and cold stress, suggesting that these genes may participate in abiotic stress responses. These findings could be used to study the role of P. ostreatus-derived C2H2-ZFs in development and stress tolerance.

The effect of light conditions on the content of selected active ingredients in anatomical parts of the oyster mushroom (Pleurotus ostreatus L.)

This study aimed to evaluate the effect of cultivation conditions in the context of light on the retention of selected vitamins, minerals and polyphenols in the stem and cap of the oyster mushroom (Pleurotus ostreatus L.). Additionally, the effect of the retention of bioactive components on the antioxidant activity of mushroom extracts was evaluated, taking into account the morphological part. Oyster mushrooms grown in the light of 200 lux had higher riboflavin content compared to mushrooms exposed to the light of lower intensity. The thiamine content of the mushrooms dropped with decreasing light intensity during cultivation. The content of biologically active compounds was found to be equal in the stem and the cap. In the case of riboflavin, it was shown that its contents in cap fractions, irrespective of the cultivation method, was statistically significantly higher than in stems. The mineral composition of caps and stems differed from each other. No differences in Zn and Cu content between the morphological parts of the mushroom studied were found. However, it was shown that the stems, regardless of the type of light, contained less iron, magnesium and sodium. Thus, it was observed that limited light exposure caused an increase in the content of total polyphenolic compounds, which did not correlate with antioxidant activity. There was no effect of the light on the antioxidant activity of mushrooms. It was also shown that stem extracts had higher antioxidant activity compared to the extracts obtained from the caps. This findings point to the possibility and potentail of use both fraction of mushrooms in the new food products development.

Optimization of enzymatic hydrolysis of Pleurotus ostreatus derived proteins through RSM and evaluation of nutritional and functional qualities of mushroom protein hydrolysates

Pleurotus ostreatus (Jacq.) P. Kumm., the second most widely cultivated oyster mushroom was grown on paddy straw, which is cheap and readily available waste material. After harvesting and drying, nutritional, and antinutritional composition of P. ostreatus were estimated using the standard assay methods. Tannin and phytic acid were present in very negligible amount (0.095 ± 0.027 mg/g and 0.150 ± 0.083 mg/g, respectively), whereas oxalate and cyanide were absent in whole mushroom. In fact, P. ostreatus was hydrolysed with commercially available proteinase K, pepsin and trypsin with different concentrations of the enzymes (0.05%, 0.10% and 0.15%), at different temperatures (30 °C, 40 °C and 50 °C) for different time periods (60, 90 and 120 min) to get the mushroom protein hydrolysates. Degree of hydrolysis and protein content varied from 4.29 ± 1.12% to 99.42 ± 0.02% and from 0.25 ± 0.07 mg/mL to 3.22 ± 0.12 mg/mL, respectively. Maximum degree of hydrolysis and the highest protein content of protein hydrolysate was obtained when using 0.15% proteinase K, at 50 °C for 120 minutes. Mushroom protein hydrolysates thus obtained exhibited improved functional characteristics such as foaming capacity, foaming stability and emulsifying property than the unhydrolysed mushroom. Based on the result of the present study, the mushroom protein hydrolysates could be served as useful ingredient for food and nutraceutical applications.