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.

This study aims to explore the use of cellulose nanocrystals (CNC) and cellulose nanofiber (CNF), obtained from unbleached fiber of oil palm empty fruit bunches (EFB), as raw materials in fabricating aerogel, using the facile technique without solvent displacement. The CNC was isolated from sulfuric acid hydrolysis, and the CNF was fibrillated using Ultra Turrax. The CNC and CNF were mixed by ultrasonication in different ratios to produce aerogel using slow freezing (−20 °C), followed by freeze-drying. The obtained aerogel was characterized as ultralightweight and highly porous material, at the density range of 0.0227 to 0.0364 g/cm3 and porosity of 98.027 to 98.667%. Interestingly, the ratio of CNC and CNF significantly affected the characteristics of the obtained aerogel. The mixed aerogel exhibited a higher specific surface area than pure CNC or CNF, with the highest value of 202.72 m2/g for the ratio of 1:3 (CNC/CNF). In addition, the crystallinity degree of obtained aerogel showed a higher value in the range of 76.49 to 69.02%, with the highest value being obtained for higher CNC content. This study is expected to provide insight into nanocellulose-based aerogel, with a promising potential for various applications.

Actinomycetes are Gram-positive bacteria with high G+C content that important for nutrient recycling of natural substrates and degradation of soil organic material. Actinomycetes can secrete enzymes to degrade organic material such as lignocellulose. Some enzymes produced by actinomycetes for degradation of lignocellulose including cellulase and xylanase. The aim of this study was to isolate actinomycetes from soil originated from Mamasa, West Sulawesi, Indonesia, and screen their cellulase and xylanase activity. A total of 57 isolates of actinomycetes have been isolated using SDS-YE method. Those isolates were screened for their cellulase and xylanase activity. The abilities of actinomycetes to degrade cellulose and xylan were observed by clear zone on CMC agar medium and xylan agar medium. Out of 57 isolates, 17 isolates produced cellulase; five isolates produced xylanase and three isolates produced both cellulase and xylanase. After the identification of potential isolates, the cellulolytic actinomycetes were identified belong to 6 genera (Asanoa, Dactylosporangium, Kitasatospora, Nonomurae, Streptomyces, and Streptosporangium). Meanwhile, the xylanolytic actinomycetes were identified belong to 3 genera (Asanoa, Kribella, and Streptomyces). The result showed that the ability of actinomycetes to produce cellulase and xylanase were very low. Therefore isolation of actinomycetes from the specific substrate is necessary to be conducted.

One major manufacturing challenge in nanocellulose production is getting the dry form of nanocellulose while maintaining its nano-size dimensions. Different drying techniques will produce nanocellulose with different sizes and morphologies. Each has its own specific application. This study performed three methods to dry nanocellulose suspension, specifically cellulose nanofiber, including freeze-drying, spray-drying, and oven drying. The morphology and particle size of the dried CNF were analyzed using Field Emission Scanning Electron Microscope (FE SEM). Sponge-like material, also known as aerogel with low density (0.01 – 0.02 g/cm3) and high porosity (98%), was obtained via freeze-drying. Meanwhile, finely grounded solidly in a spherical and irregular form has resulted from the spray drying process of CNF, with an average diameter of less than 2 μm. Oven-dried CNF formed rigid thin film with a rough surface. However, the FE-SEM micrograph indicated that the nanoscale dimension of the oven-dried CNF has no longer existed. Therefore, oven-drying is not suggested as a drying method for nanocellulose.

Butanol, a rising star in biofuel, can be produced by two approaches, petrochemically and biologically. Currently, the most promising route for butanol production is by fermentation using Clostridium species through an anaerobic condition. However, similar to other biofuels, feedstock has greatly influenced the production of biobutanol and the search for inexpensive and abundant raw material is an absolute requirement for a cost-effective process. Second-generation biobutanol which is produced from lignocellulosic biomass of agricultural and forestry waste not only meets the requirement but also alleviates competition with food crops and thereby solves the problems of food scarcity from the first generation biobutanol. This paper delivered the latest and update information regarding biobutanol production specifically second-generation biobutanol in terms of production method, recovery, purification, status, and technoeconomic.  Keyword: biobutanol, lignocellulose, purification, recovery, technoeconomic