• 제목/요약/키워드: environmental microbiology

검색결과 1,791건 처리시간 0.05초

Genome-Wide Transcriptomic Analysis of n-Caproic Acid Production in Ruminococcaceae Bacterium CPB6 with Lactate Supplementation

  • Lu, Shaowen;Jin, Hong;Wang, Yi;Tao, Yong
    • Journal of Microbiology and Biotechnology
    • /
    • 제31권11호
    • /
    • pp.1533-1544
    • /
    • 2021
  • n-Caproic acid (CA) is gaining increased attention due to its high value as a chemical feedstock. Ruminococcaceae bacterium strain CPB6 is an anaerobic mesophilic bacterium that is highly prolific in its ability to perform chain elongation of lactate to CA. However, little is known about the genome-wide transcriptional analysis of strain CPB6 for CA production triggered by the supplementation of exogenous lactate. In this study, cultivation of strain CPB6 was carried out in the absence and presence of lactate. Transcriptional profiles were analyzed using RNA-seq, and differentially expressed genes (DEGs) between the lactate-supplemented cells and control cells without lactate were analyzed. The results showed that lactate supplementation led to earlier CA p,roduction, and higher final CA titer and productivity. 295 genes were substrate and/or growth dependent, and these genes cover crucial functional categories. Specifically, 5 genes responsible for the reverse β-oxidation pathway, 11 genes encoding ATP-binding cassette (ABC) transporters, 6 genes encoding substrate-binding protein (SBP), and 4 genes encoding phosphotransferase system (PTS) transporters were strikingly upregulated in response to the addition of lactate. These genes would be candidates for future studies aiming at understanding the regulatory mechanism of lactate conversion into CA, as well as for the improvement of CA production in strain CPB6. The findings presented herein reveal unique insights into the biomolecular effect of lactate on CA production at the transcriptional level.

Cultivable Bacterial Community Analysis of Dairy Activated Sludge for Value Addition to Dairy Wastewater

  • Biswas, Tethi;Chatterjee, Debasmita;Barman, Sinchini;Chakraborty, Amrita;Halder, Nabanita;Banerjee, Srimoyee;Chaudhuri, Shaon Ray
    • 한국미생물·생명공학회지
    • /
    • 제47권4호
    • /
    • pp.585-595
    • /
    • 2019
  • Analysis of bacterial communities based on their 16S rDNA sequences revealed the predominance of Proteobacteria (Aeromonas sp., Acinetobacter sp. and Thaueraamino aromatica sp.) and uncultured bacterium in activated sludge from the effluent treatment plant (ETP) of Mother Dairy, Calcutta (India). Each isolate was used for bioremediation of dairy wastewater with simultaneous conversion of nitrogenous pollutants into ammonia. A consortium developed using seven of these isolates and three Bacillus strains from different environmental origins could reduce 93% nitrate with simultaneous production of ammonia (626 ㎍/100 ml) within 20 h in non-aerated, immobilized conditions as compared to 82% nitrate reduction producing 2.4 ㎍/100 ml ammonia in 96 h with extensive aeration in a conventional ETP. The treated ammonia-rich effluent could be used instead of freshwater and fertilizer during cultivation of mung bean with 1.6-fold increase in grain yield. The ETP with the surrounding agricultural land makes this process a zero liquid discharge technology for using the biofertilizer generated. In addition, the process requires minimal energy supporting sustained environmental health. This method is thus proposed as an alternative approach for small-scale dairy ETPs.

Antioxidant and Antifungal Activity of Endophytic Fungi Associated with Agarwood Trees

  • Hidayat, Asep;Turjaman, Maman;Faulina, Sarah Asih;Ridwan, Fadel;Aryanto, Aryanto;Najmulah, Najmulah;Irawadi, Tun Tedja;Iswanto, Apri Heri
    • Journal of the Korean Wood Science and Technology
    • /
    • 제47권4호
    • /
    • pp.459-471
    • /
    • 2019
  • Several species of Aquilaria and Gyrinops are native to Indonesia and well known as agarwood-producing trees with a high economic value. Their bioactive compounds have a wide spectrum of uses, such as in medicine and cosmetics. These genera have undergone extensive search for novel bioactive compounds. The purpose of this study was to isolate, identify, and characterize the endophytic fungi community associated with Aquilaria malaccensis, A. microcarpa, Gyrinops versteegii, and A. crassna trees and investigate their bioactive properties as antioxidant agents and antagonists. A total of 50 fungi were successfully isolated from different tissues of the four species of agarwood-producing trees. Two isolates exhibited strong antioxidant activity, namely, Apodus oryzae (R2MC3A, $IC_{50}$ 60.92 mg/mL) and Diaporthe sp. (P1DS1[C], $IC_{50}$ 76.65 mg/mL). Two isolates, Pestalotiopsis theae (P3BS3[B]) and Curvularia sp. (P2CD3A), showed >75% antifungal activity against pathogenic Fusarium solani. The results revealed that endophytic fungi associated with the studied agarwood-producing trees had potential antioxidant and antifungal activities for further applications in biotechnology.

Protease Inhibitor Production using Streptomyces sp. SMF13

  • Kim, In-Seop;Kim, Hyoung-Tae;Lee, Hyun-Sook;Lee, Kye-Joon
    • Journal of Microbiology and Biotechnology
    • /
    • 제1권4호
    • /
    • pp.288-292
    • /
    • 1991
  • The aim of the current study is to evaluate the effects of medium compositions on the production of protease inhibitor in Streptomyces sp. SMF13. The production of protease inhibitor was counter-currently linked to extra-cellular protease, which were regulated by the culture conditions. Nitrogen source was the most critical ingredient affecting the production of protease inhibitor and protease. Carbon source was an important factor to determine the culture pH which affected very clearly the formation of protease and protease inhibitor. Inorganic phosphate inhibited the protease inhibitor production which was linked to the cell growth rate, although the optimal conditions for the production of protease inhibitor were not favouring to the cell growth.

  • PDF