Characterizing fungal communities in medicinal and edible Cassiae Semen using high-throughput sequencing.

Cassiae Semen (CS) has been widely used as roasted tea and traditional Chinese medicine for decades. However, CS is easily contaminated by fungi and mycotoxins during pre-harvest and post-harvest process, thus posing a potential threat to consumer health. In this study, we used the Illumina MiSeq PE300 platform and targeted the internal transcribed spacer 2 sequences to survey the occurrence of fungi in raw and roasted CS samples. Results showed the fungal contamination in all 12 test samples. Ascomycota was the prevailing fungus at the phylum level, with the relative abundance of 66.50%-99.42%. At the genus level, Aspergillus, Cladosporium, and Penicillium were the most dominant genera, accounting for 0.66%-85.51%, 0.20%-29.11%, and 0.11%-32.92% of the fungal reads, respectively. A total of 68 species were identified, among which six potential toxigenic fungi belonging to Aspergillus, Penicillium, Candida, and Schizophyllum genera were detected. Moreover, differences in fungal communities were observed in raw and roasted CS samples. In conclusion, amplicon sequencing is feasible for analyzing fungal communities in CS samples, which provides a new approach to investigate the fungal contamination in edible-medicinal herb, thereby ensuring food safety and drug efficacy.

Endophytic actinomycetes associated with Cinnamomum cassia Presl in Hoa Binh province, Vietnam: Distribution, antimicrobial activity and, genetic features.

Endophytic microbes associated with medicinal plants are considered to be potential producers of various bioactive secondary metabolites. The present study investigated the distribution, antimicrobial activity and genetic features of endophytic actinomycetes isolated from the medicinal plant Cinnamomum cassia Presl collected in Hoa Binh province of northern Vietnam. Based on phenotypic characteristics, 111 actinomycetes were isolated from roots, stems and leaves of the host plants by using nine selective media. The isolated actinomycetes were mainly recovered from stems (n = 67; 60.4%), followed by roots (n = 29; 26.1%) and leaves (n = 15; 13.5%). The isolates were accordingly assigned into 5 color categories of aerial mycelium, of which gray is the most dominant (n = 42; 37.8%), followed by white (n = 33; 29.7%), yellow (n = 25; 22,5%), red (n = 8; 7.2%) and green (n = 3; 2.7%). Of the total endophytic actinomycetes tested, 38 strains (occupying 34.2%) showed antimicrobial activity against at least one of nine tested microbes and, among them, 26 actinomycetes (68.4%) revealed anthracycline-like antibiotics production. Analysis of 16S rRNA gene sequences deposited on GenBank (NCBI) of the antibiotic-producing actinomycetes identified 3 distinct genera, including Streptomyces, Microbacterium, and Nocardia, among which Streptomyces genus was the most dominant and represented 25 different species. Further genetic investigation of the antibiotic-producing actinomycetes found that 28 (73.7%) and 11 (28.9%) strains possessed genes encoding polyketide synthase (pks) and nonribosomal peptide synthetase (nrps), respectively. The findings in the present study highlighted endophytic actinomycetes from C. cassia Presl which possessed broad-spectrum bioactivities with the potential for applications in the agricultural and pharmaceutical sectors.

Antimicrobial and Cytotoxic Properties of Bioactive Metabolites Produced by Streptomyces cavourensis YBQ59 Isolated from Cinnamomum cassia Prels in Yen Bai Province of Vietnam.

The endophytic actinomycete strain YBQ59 was isolated from Cinnamomum cassia Prels in Yen Bai province (21°53'14″N; 104°35'9″E) of northern Vietnam. Based on analysis of morphological, physiological characteristics and 16S rRNA gene sequence (GenBank Acc. No. MF950891), the strain YBQ59 possessed high similarity to Streptomyces cavourensis subsp. cavourensis strain NRRL 2740, therefore assigned as S. cavourensis YBQ59. The ethyl acetate extract of the YBQ59 culture broth isolated eight pure secondary metabolites, identified as 1-monolinolein (1), bafilomycin D (2), nonactic acid (3), daidzein (4), 3'-hydroxydaidzein (5), 5,11-epoxy-10-cadinanol (6), prelactone B (7), and daucosterol (8). Compounds 1, 3-8 were reported for the first time from S. cavourensis. Compounds 1-5 exhibited antimicrobial activities against both methicillin-resistant Staphylococcus aureus ATCC 33591 (MRSA) and methicillin-resistant Staphylococcus epidermidis ATCC 35984 (MRSE) among which the compound 1 revealed the strongest effects with minimum inhibitory concentrations of 8.5 and 14.6 µg/mL, respectively. The compound 2 showed high potential effect against MRSA (MIC of 11.1 µg/mL) but less effect against MRSE (MIC of 30.3 µg/mL). The cytotoxicity of the compounds 1-7 was investigated against human lung adenocarcinoma EGFR-TKI-resistant cells, among which compounds 1, 2, and 5 exhibited the strong effect against A549 cells with IC50 values of 3.6, 6.7, and 7.8 µM, respectively. Taken together, the experimental findings in this study suggested that the compounds 1 and 2 could be reproducible metabolites applicable for inhibition of both drug-resistant bacteria and cancer cell lines.

Environmental isolation of Cryptococcus neoformans and Cryptococcus gattii from living trees in Guindy National Park, Chennai, South India.

We report for the first time the environmental isolation of Cryptococcus neoformans from decaying wood and bark debris of living trees in Guindy National Park, Chennai, South India. Of the 40 trees screened, four isolates of Cryptococcus species were recovered of which two were Cryptococcus gattii, one was C. neoformans and one was untypable. The isolation of C. neoformans from Eucalyptus globulus and C. gattii from Cassia marginata in this study constitutes the first record of the natural occurrence of C. neoformans varieties in these tree species anywhere in the world. The isolation of C. gattii from Syzygium cumini represents the first isolation from South India.

Natural formation of styrene by cinnamon mold flora.

Tests on 106 dried pure cinnamon samples of diverse origins showed that some samples were naturally contaminated with high levels of styrene, up to 524 microg/g. Styrene taint can be associated with high water activity levels and thus with microorganism growth. The mold flora of a Korintji cinnamon sample in which styrene had been found at a 50 microg/g concentration was analyzed and 5 species of mold were isolated. An investigation into the ability of the 5 species of mold to produce styrene showed that 3 of them--namely, Penicillium citrinum, Penicillium oxalicum, Aspergillus niger--produced styrene in vitro in buffered peptone water at 25 degrees C within 5 d in the presence of several natural cinnamon volatile constituents containing the styrene structure. The conversion of these compounds into styrene by these 3 cinnamon fungal species has never been previously reported. A standardized inoculation with the 3 mold species was carried out on 10 g cinnamon samples of various origins followed by a 10-d incubation and highlighting styrene production except for Sri Lanka origin.