Perilla frutescens seed agar, a new medium for identification of the Cryptococcus species complex: evaluation for all major molecular types

Banana blossom agar (BABA), a new medium to isolate members of the Cryptococcus neoformans/Cryptococcus gattii species complex useful for resource limited countries

Isolation of representatives of the Cryptococcus neoformans/Cryptococcus gattii species complex can be made using dopamine containing media, such as Niger seed agar and l-DOPA agar. Here, we describe an alternative medium that uses banana flowers. Banana is a dopamine containing fruit and is widely available in tropical and subtropical countries that have high numbers of cryptococcosis patients. This banana blossom-based agar is useful for the enrichment of isolates of the C. neoformans/C. gattii species complex from environmental and clinical materials. The banana blossom agar (BABA) with and without creatinine can differentiate between the melanin forming isolates of the C. neoformans/C. gattii species complex from other yeasts that do not form melanin.

Pyrolytic and kinetic characteristics of the thermal decomposition of Perilla frutescens polysaccharide

The thermal decomposition of Perilla frutescens polysaccharide was examined by thermogravimetry, differential thermogravimetry, and differential thermal analysis. The results showed that the mass loss of the substance proceeded in three steps. The first stage can be attributed to the expulsion of the water from ambient temperature to 182°C. The second stage corresponded to devolatilization from 182°C to 439°C. The residue slowly degraded in the third stage. The weight loss in air is faster than that in nitrogen, because the oxygen in air accelerated the pyrolytic reaction speed reaction. The heating rate significantly affected the pyrolysis of the sample. Similar activation energies of the degradation process (210-211 kJ mol⁻¹) were obtained by the FWO, KAS, and Popescu techniques. According to Popescu mechanism functions, the possible kinetic model was estimated to be Avrami-Erofeev 20 g(α) = [-ln(1-α)]⁴.