Accelerated rate storage and viability test of Basidiomycetous fungal strains were cryopreserved at - 80° C

Abstract

Maintaining and preserving microbes such as fungal cultures are essential elements in systematics and biodiversity studies, fundamental part in ex situ conservation and underpinning biotechnology. Majority of Basidiomycetous fungal strains and mushroom cultures in Indonesia are maintained and preserved by serial transfer. This short term active metabolism-based preservation was simple, but it can not be implemented for maintain and storage in the large numbers of fungal cultures due to time consuming and labour intensive. Recently, permanent long term and inactive metabolism-based preservation such as cryopreservation were introduced and implemented for resolved the problems. The objective of this study was to examine the effectiveness of cryopreservation at -80° C with 10% (v/v) glycerol and 5% (g/v) trehalose as cryoprotectant into the 50 strains of the Basidiomycetous fungi from Indonesian Culture Collection (InaCC). The Basidiomycetous fungal cultures were used consists of several taxa such as; Agaricus, Agrocybe, Auricularia, Coprinus, Ganoderma, Lentinula, Phanerochaete, Pleurotus and Trametes. The accelerated storage and viability tests were performed by thawed and revived the stored cultures after 2 weeks and 12 months storage at -80°C. The results showed there are no viability loss among the 50 strains were observed, however there is a distinct acclimatization time and growth rate between cultures were stored at -80°C for 48 hours and more than 3 years. Strains were stored for 48 hours at -80°C begin to grow after 3 days of incubation, whereas cultures were stored at -80°C for more than 3 years begin to grow optimally after 5 days of incubation. Nevertheless, significant differences in acclimatization time and growth rate in both storage periods were not seen in Ganoderma, Phanerochaete, Pleurotus, and Trametes cultures. In general, this long term inactive metabolism-based preservation method is effectively applied for maintain and keep the viability of Basidiomycetous fungal cultures in InaCC.