No abstract

No abstract

Background Indonesia is one of the Southeast Asian countries with high case numbers of COVID-19 with up to 4.2 million confirmed cases by 29 October 2021. Understanding the genome of SARS-CoV-2 is crucial for delivering public health intervention as certain variants may have different attributes that can potentially affect their transmissibility, as well as the performance of diagnostics, vaccines, and therapeutics. Objectives We aimed to investigate the dynamics of circulating SARS-CoV-2 variants over a 15-month period in Bogor and its surrounding areas in correlation with the first and second wave of COVID-19 in Indonesia. Methods Nasopharyngeal and oropharyngeal swab samples collected from suspected patients from Bogor, Jakarta and Tangerang were confirmed for SARS-CoV-2 infection with RT-PCR. RNA samples of those confirmed patients were subjected to whole genome sequencing using the ARTIC Network protocol and sequencer platform from Oxford Nanopore Technologies (ONT). Results We successfully identified 16 lineages and six clades out of 202 samples (male n = 116, female n = 86). Genome analysis revealed that Indonesian lineage B.1.466.2 dominated during the first wave (n = 48, 23.8%) while Delta variants (AY.23, AY.24, AY.39, AY.42, AY.43 dan AY.79) were dominant during the second wave (n = 53, 26.2%) following the highest number of confirmed cases in Indonesia. In the spike protein gene, S_D614G and S_P681R changes were dominant in both B.1.466.2 and Delta variants, while N439K was only observed in B.1.466.2 (n = 44) and B.1.470 (n = 1). Additionally, the S_T19R, S_E156G, S_F157del, S_R158del, S_L452R, S_T478K, S_D950N and S_V1264L changes were only detected in Delta variants, consistent with those changes being characteristic of Delta variants in general. Conclusions We demonstrated a shift in SARS-CoV-2 variants from the first wave of COVID-19 to Delta variants in the second wave, during which the number of confirmed cases surpassed those in the first wave of COVID-19 pandemic. Higher proportion of unique mutations detected in Delta variants compared to the first wave variants indicated potential mutational effects on viral transmissibility that correlated with a higher incidence of confirmed cases. Genomic surveillance of circulating variants, especially those with higher transmissibility, should be continuously conducted to rapidly inform decision making and support outbreak preparedness, prevention, and public health response.

No abstract

No abstract

The current interest in exploring white-rot fungi has been concentrated in increasing their ligninolityc enzyme production such as laccase and manganese peroxidase (MnP) due to the great value in industrial application. The presence of appropiate inducers can enhance the enzyme production. Hence, the aim of the study was to investigate the activity of  laccase and MnP in response to various aromatic compounds. The fungus Trametes hirsuta was cultured in Glucose Yeast Peptone (GYP) broth (pH 5.0) with the addition of 0.5% of sorghum biomass as substrate. The cultures were then incubated on rotary shaker at 150 rpm at 27oC. The 7-day-old cultures were then supplemented with different aromatic compounds, namely caffeic acid, gallic acid, syringic acid, trans-cinnamic acid, vanillin, and veratryl alcohol. Our results demonstrated that veratryl alcohol, gallic acid and vanillin gave an inductive effect on the value of laccase and MnP activities, with vanillin showing the highest induction. On the contrary, the level of laccase and MnP activities remained low in the presence of aromatic compound such as syringic acid, trans-cinnamic acid and caffeic acid. To conclude, our study reveals that aromatic compounds can be potential as inducers and may contribute to the improvement of laccase and MnP productivity by T. hirsuta.

In many food industries, glucoamylase is extensively applied because of its ability to convert oligosaccharides into glucose. Recently, mutagenic treatments of Aspergillus awamori have been conducted to improve and enhance glucoamylase production. This research was focused on the study of glucoamylase production by strains of A. awamori after being exposed to ultra-violet (UV) irradiation. The parental strain was cultivated on the PDA plates and treated by exposing under UV lamp from 0 to 90 minutes with the time intervals of 30 min. Solid state fermentation was carried out to produce glucoamylase using cassava peel as a substrate. As compared to all strains, the mutant strain of A. awamori after being treated by 30 min of UV exposure time gave the highest activity of glucoamylase at 5.9 U/ml. The activity was two fold higher than the parental strain. The same mutant strain also reached its maximum value of total protein content at 97.31 µg/ml and 23% higher than parental strain. Glucoamylase production can be achieved and improved by the strain of A. awamori after UV mutagenic treatment.

Tea is one of the most popular beverages in the world. Produced from Camellia sinensis leaves, tea has been studied to provide health benefits due to the content of important metabolites. This study aimed to investigate the catechin contents, antioxidant, and antibacterial activities of Indonesian tea varieties, namely green tea, black tea, and white tea. Tea infusion was prepared by extracting 1 g of each sample into 10 mL of distilled water and incubated at 80 °C for 60 min. The catechin and epigallocatechin gallate (EGCG) contents of tea extracts were determined using high-performance liquid chromatography (HPLC). Antioxidant activity was measured using the free radical method with 2,2-diphenyl-1-pycrylhidrazyl (DPPH), while antimicrobial activity was assesed using paper disc diffusion assay. The results indicated that green tea had the highest contents of catechin (646 ± 17.14 mg/L) and EGCG (997.8 ± 36.72 mg/L), and antioxidant activity with IC50 of  5.65 µg/mL. Furthermore, green tea and white tea extracts showed inhibitory activity against Gram-positive bacteria such as Micrococcus luteus, Bacillus subtilis, and Staphylococcus aureus whereas black tea had no activity against all bacterial strains tested. Generally, we concluded that white tea and green tea contributed to the higher content of catechins and exhibited strong antioxidant and antibacterial properties.