http://chineseinput.net/에서 pinyin(병음)방식으로 중국어를 변환할 수 있습니다.
변환된 중국어를 복사하여 사용하시면 됩니다.
Insights into Systems for Iron-Sulfur Cluster Biosynthesis in Acidophilic Microorganisms
Myriam Pérez,Braulio Paillavil,Javiera Rivera-Araya,Claudia Muñoz-Villagrán,Omar Orellana,Renato Chávez,Gloria Levicán 한국미생물·생명공학회 2022 Journal of microbiology and biotechnology Vol.32 No.9
Fe-S clusters are versatile and essential cofactors that participate in multiple and fundamental biological processes. In Escherichia coli, the biogenesis of these cofactors requires either the housekeeping Isc pathway, or the stress-induced Suf pathway which plays a general role under conditions of oxidative stress or iron limitation. In the present work, the Fe-S cluster assembly Isc and Suf systems of acidophilic Bacteria and Archaea, which thrive in highly oxidative environments, were studied. This analysis revealed that acidophilic microorganisms have a complete set of genes encoding for a single system (either Suf or Isc). In acidophilic Proteobacteria and Nitrospirae, a complete set of isc genes (iscRSUAX-hscBA-fdx), but not genes coding for the Suf system, was detected. The activity of the Isc system was studied in Leptospirillum sp. CF-1 (Nitrospirae). RT-PCR experiments showed that eight candidate genes were co-transcribed and conform the isc operon in this strain. Additionally, RT-qPCR assays showed that the expression of the iscS gene was significantly up-regulated in cells exposed to oxidative stress imposed by 260 mM Fe2(SO4)3 for 1 h or iron starvation for 3 h. The activity of cysteine desulfurase (IscS) in CF-1 cell extracts was also upregulated under such conditions. Thus, the Isc system from Leptospirillum sp. CF-1 seems to play an active role in stressful environments. These results contribute to a better understanding of the distribution and role of Fe-S cluster protein biogenesis systems in organisms that thrive in extreme environmental conditions.
Bonifacio O. Pasion,Carolyn DP. Barrias,Milagrosa P. Asuncion,Abelardo H. Angadol,Robert R. Pabiling,Arsenio Pasion Jr.,Archiles A. Braulio,Agaton M. Baysa Jr. 국립중앙과학관 2021 Journal of Asia-Pacific Biodiversity Vol.14 No.1
Riparian zones are a small portion of a watershed but hold a diverse and important ecosystem functioning. We assessed diversity and carbon density of pole (5e10 cm DBH) and canopy (>10 cm DBH)trees along a riparian zone in Pasonanca Natural Park, southern Philippines. We identified 66 species,which included 41 canopy and 54 pole tree species, and comprised 46 indigenous, 18 Philippine endemics,and two exotic species. We recorded eight vulnerable (VU) and two endangered (EN) speciesunder the Philippine Red List, whereas five VU, three EN, and six critically endangered (CR) species wererecorded under the IUCN Global Red List. We estimated the Hill number of canopy trees at 60.91 12.14species and the Shannon diversity H’ was 49.57 5.15, whereas the pole tree was 77.87 12.60 specieswith diversity H’ of 33.07 3.77. The estimated carbon density was 128.42 39.04 MgC ha 1, majorityfrom canopy trees (101.51 63.52 MgC ha 1). We found an asymptotic and strong positive relationship(R2 ¼ 0.81; p ¼ <0.001) between species dominance and carbon density. Our result highlighted the roleof dominant species in maintaining ecosystem function, which can be considered when managing riparianecosystems as they perform better in storing and sequestering carbon.