Vol 8, No 2 (2023)

Table of Contents

Biotechnology and Applications

234 Views, 40 PDF Downloads
Katewadee Boonyapakron, Kanoknart Prabmark, Benjarat Bunterngsook, Nattapol Arunrattanamook, Thanchanok Preechakun, Marisa Raita, Kanokarn Kocharin, Verawat Champreda
DOI:10.26789/AEB.2023.02.005

Abstract

Sugarcane trash (SCT) is a promising underused lignocellulosic material for the production of chemicals in biorefineries. In this work, we studied the use of SCT to produce lactic acid (LA), an important commodity chemical used in food and bioplastic industries. SCT was pretreated with a hydrothermal liquid hot water step followed by saccharification with Cellic® CTec2, which resulted in the SCT hydrolysate containing 30.42±0.08 g/L total sugar, equivalent to 88.10% and 42.92% glucose and xylose recoveries, respectively. Screening of stereospecific LA production exhibited Lactococcus lactis BCC 68868 and Leuconostoc lactis BCC 62792 efficiently utilized SCT hydrolysate converted to entirely L-LA and D-LA, respectively. A detoxification step was unnecessary for hydrolysate fermentation to LA, and the addition of CaCO3 for pH control enabled complete hydrolysate utilization. La. lactis BCC 68868 converted SCT hydrolysate into optically pure L-LA at 19.34 g/L, equivalent to a conversion yield of 0.95 g LA/g sugar. While Le. lactis BCC 62792 produced D-LA at 10.39 g/L, equivalent to a conversion yield of 0.45 g LA/g sugar with ethanol and acetic acid as the by-products, suggesting their homofermentative and heterofermentative characteristic, respectively. This work demonstrates a promising strategy to produce enantiomerically defined LA from this underutilized agricultural waste.

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44-51
281 Views, 27 PDF Downloads
Md. Saddam Hossain, Md. Rakibul Hasan, Debabrata Karmakar, Nishat Tasnim, Razia Sultana, Sharmin Akter, Md. Rezaul Karim
DOI:10.26789/AEB.2023.02.004

Abstract

Overpopulation in world has created immense pressure on agricultural land to increase crops production by using excess chemical fertilizers, pesticides, and plant growth regulators. Nowadays, biofertilizer is one of the best concerns of research interest for sustainable development in agriculture and environment. About 30 soil bacteria were isolated from three different locations in Bangladesh by growing on nitrogen-free selective media and primarily had been categorized based on colony features. However, to short out the biofertilizer and biocontrol potential bacteria several assay had been conducted including nitrogen-fixing assay, ammonia production assay, phosphate solubilizing assay, IAA production assay, siderophores production assay, amylase production assay, biocontrol assay, and seed germination bioassay. Different species of Rhizobium, Bacillus, Paraburkholderia, Priestia, Arthrobacter, Pseudarthrobacter, Rhodanobacter, Flavobacterium, Mucilaginibacter, and Sphingomonas were identified by analyzing 16S rRNA gene partial sequence analysis by BLASTn that revealed many of these act as biofertilizer. Moreover, the antibiotic resistance tests of biofertilizer potential isolates and all others intensive data analysis in respect of biofertilizer functionality revealed that Paraburkholderia sacchari is the best while Priestia megaterium, Bacillus zanthoxyli, Arthrobacter globiformis, and Bacillus wiedmanni have also the potentiality to be biofertilizer. The outcome will help the researchers and industries to develop biofertilizer for crops plant.

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Research Articles

360 Views, 49 PDF Downloads
Maya Shovitri, Hefdiyah Hefdiyah, Titi Rindi Antika, Nengah Dwianita Kuswytasari, Nur Hidayatul Alami, Enny Zulaika, Seung Wook Kim, Min Kyu Oh
DOI:10.26789/AEB.2023.02.003

Abstract

Plastics have become inevitable needs in modern society due to their attractive properties, including thermostability, lightweight, flexibility, superior insulation, and low cost, which have led to massive production. Their persistence and challenges in disposal have detrimental effects on the environment leading to the development of a promising degradation process which is efficient, time-saving, and cost-effective. This study focused on discovering the potential plastic-degrading bacteria isolated from plastic-contaminated mangrove sediment in the Wonorejo area. We buried a commercially available plastic bag in the polluted mangrove sediment for 16 weeks. Our results showed that indigenous bacteria formed a biofilm on the plastic surface leading to a plastic dry weight loss of up to 12%. FTIR analysis revealed obvious transmittance attenuations in the buried plastic polymer, suggesting that their chemical properties may have been interrupted due to bacterial activity. Further, bacteria isolation and biochemical screening revealed that they were primarily dominated by Bacillus. According to 16S rRNA sequencing, they were identified as Brevibacilllus (BIO-B), Stenotrophomonas (BIO-G), and Lysinibacillus (SOI-C). The three genera mentioned earlier exhibited a detectable level of plastic-degrading activity and possessed lipolytic, ligninolytic, and alkane-degrading activities. Stenotrophomonas (BIO-G) showed a degradation activity on low-density polyethylene (LDPE) represented by a plastic dry weight loss of up to 8.9% within 4 weeks. As expected, plastic treated with BIO-G showed transmittance attenuation in FTIR analysis, albeit with a lower percentage than that treated with indigenous bacteria. Moreover, SEM analysis reveals changes in the morphological surface of plastic. Together, FTIR and SEM analysis indicated that bacteria disrupt both the chemical structure and morphological appearance of plastic polymer upon degradation process. These results denote that BIO-G indeed composes the aforementioned indigenous bacteria from polluted mangrove sediment. Thus, our study suggests the indigenous bacteria isolated from contaminated areas produced plastic-degrading enzymes and secreted to the environment to break down plastic compounds.

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18-28
236 Views, 58 PDF Downloads
Somasundaram Ramesh, Radhakrishnan Nagalakshmi
DOI:10.26789/AEB.2023.02.002

Abstract

Microplastic contamination in the Chennai coastal region is a growing concern due to the intake of abandoned garbage from various sources. This study aimed to assess the extent of microplastic contamination by analyzing microplastic trash collected from 25 spots along the Tamil Nadu coast, spanning a distance of 1076 kilometers. The results revealed that microplastic contamination was more prevalent during higher wave conditions compared to lower tides. Shorelines near riverbanks exhibited significantly higher quantities of microplastics than those affected by fisheries and tourist activities. The main types of microplastics found were polyethylene, polypropylene, and polystyrene, with plastic shards comprising the majority of the trash (47-50%). Furthermore, analyses of fish species collected from shore regions showed that 10.1% of the fishes had consumed plastic particles. This emphasizes the potential risk of microplastics entering the marine food chain. The study highlights the need for microplastic filtering from estuaries, coastline waters, and other potential sources. In conclusion, microplastic contamination poses a serious hazard to the Chennai coastal region. Urgent measures are required to mitigate and reduce microplastic pollution, particularly near river openings, to protect the marine ecosystem and the food chain. Efforts should focus on preventing the entry of microplastics into the environment and promoting sustainable waste management practices to safeguard the coastal ecosystem.

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10-17
397 Views, 80 PDF Downloads
Almira Saparbekova, Alina Altekey, Galina Seitmagzimova, Anar Esimova, Darikha Kudasova, Zhuldyz Ibraimova
DOI:10.26789/AEB.2023.02.001

Abstract

The pulp and paper industry is at its peak due to the annual growth in demand for paper products which includes packaging board, hygienic paper products, printing papers and the list is endless. To date, the main source of raw materials for pulp and paper production is wood. However, its use and the use of standard flow charts in pulp and paper production creates environmental problems. For example, deforestation to obtain raw materials leads to a disruption of biogeocenoses, and technology using alkalis and acids are sources of toxic wastewater that pollute the hydrosphere and lithosphere. In order to avoid the above environmental problems, other options for sustainable sources of raw materials can be considered, such as agricultural waste - straw. By its natural origin, straw is a non-woody plant, which will significantly simplify the flow chart of pulp and paper production, on the one hand, and on the other hand, the use of straw in production will help to reduce the risks of early global warming, since most of the straw is burned in the fields. As far as toxic wastewater emissions are concerned, they can be drastically reduced through the biological degradation of straw lignin to produce pure pulp. Biodegradation of lignin can be produced by widespread wood-destroying fungi due to their ability to synthesize lignin-degrading enzymes. Thus, the use of biological agents in pulp and paper production will make it possible to eliminate the use of caustic acids and alkalis.

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