Coexisting mechanisms of bacterial community are changeable even under similar stable conditions in a chemostat culture

2021 ◽  
Vol 131 (1) ◽  
pp. 77-83
Author(s):  
Fatma Azwani Abdul Aziz ◽  
Kenshi Suzuki ◽  
Masahiro Honjo ◽  
Koki Amano ◽  
Abd Rahman Jabir Bin Mohd Din ◽  
...  
2020 ◽  
Vol 85 ◽  
pp. 183-196
Author(s):  
Y Sun ◽  
J Liu ◽  
Q Yao ◽  
J Jin ◽  
X Liu ◽  
...  

Viruses are the most abundant and ubiquitous biological entities in various ecosystems, yet few investigations of viral communities in wetlands have been performed. To address this data gap, water samples from 6 wetlands were randomly collected across northeast China; viruses in the water were concentrated by sequential tangential flow filtration, and viral communities were assessed through randomly amplified polymorphic DNA-PCR (RAPD-PCR) with 4 decamer oligonucleotide primers. Principal coordinate analysis and hierarchical clustering analysis of the DNA fingerprints showed that viral community compositions differed among the water samples: communities in the 2 coastal wetlands were more similar to each other than to those in the 4 freshwater wetlands. The Shannon-Weaver index (H) and evenness index (E) of the RAPD-PCR fingerprint also differed among the 6 wetlands. Mantel test revealed that the changes in viral communities in wetland water were most closely related to the water NH4+-N and inorganic C content, followed by total K, P, C and NO3--N. DNA sequence analysis of the excised bands revealed that viruses accounted for ~40% of all sequences. Among the hit viral homologs, the majority belonged to the Microviridae. Moreover, variance partitioning analysis showed that the viral community contributed 24.58% while environmental factors explained 30.56% of the bacterial community variation, indicating that the bacterial community composition was strongly affected by both viral community and water variables. This work provides an initial outline of the viral communities from different types of wetlands in northeast China and improves our understanding of the viral diversity in these ecosystems.


2014 ◽  
Vol 73 (1) ◽  
pp. 51-67 ◽  
Author(s):  
A Jain ◽  
M Bandekar ◽  
J Gomes ◽  
D Shenoy ◽  
RM Meena ◽  
...  

2017 ◽  
Vol 14 (1) ◽  
pp. 53
Author(s):  
Arwan Apriyono ◽  
Sumiyanto Sumiyanto ◽  
Nanang Gunawan Wariyatno

Gunung Tugel is an area that located Patikraja Region, Southern Banyumas. Thetopography of the area is mostly mountainous with a slope that varies from flat to steep. Thiscondition makes to many areas of this region potentially landslide. In 2015, a landslideoccurred in Jalan Gunung Tugel. The Landslide occurred along 70 meters on the half of theroad and causing traffic Patikraja-Purwokerto disturbed. To repair the damage of the road andavoid further landslides, necessary to analyze slope stability. This study is to analyze landslidereinforcement that occurred at Gunung Tugel and divides into 3 step. The first step is fieldinvestigation to determine the condition of the location and dimensions of landslides. Thesecond step is to know the soil parameters and analyzes data were obtained from the field. Andthe final step is analyzed of the landslide reinforcement by using data obtained from thepreceding step. In this research, will be applied three variations of reinforcement i.e. retainingwall, pile foundation and combine both of pile foundations and retaining wall. Slope stabilityanalysis was conducted using limit equilibrium method. Based on the analysis conducted onthe three variations reinforcement, combine both of pile foundations and retaining wall morerecommended. Application of and combine both of pile foundations and retaining wall is themost realistic option in consideration of ease of implementation at the field. From thecalculations have been done, in order to achieve stable conditions need retaining wall withdimensions of 2 meters high with 2,5 meters of width. DPT is supported by two piles of eachcross-section with 0.3 meters of diameter along 10 meters with 1-meter in space. Abstrak: Gunung Tugel adalah salah satu daerah yang terletak di Kecamatan PatikrajaKabupaten Banyumas bagian selatan. Kondisi topografi daerah tersebut sebagian besar berupapegunungan dengan kemiringan yang bervariasi dari landai sampai curam. Hal inimenyebabkan banyak daerah di wilayah Gunung Tugel yang berpotensi terjadi bencana tanahlongsor. Pada tahun 2015, peristiwa longsor kembali terjadi di ruas Jalan Gunung Tugel.Kelongsoran yang terjadi sepanjang 70 meter pada separuh badan jalan tersebut menyebabkanarus lalu lintas patikraja-purwokerto menjadi terganggu. Untuk memperbaiki kerusakan jalandan mencegah kelongsoran kembali, diperlukan analisis perkuatan tanah terhadap lerengtersebut. Studi analisis penanggulangan kelongsoran jalan yang terjadi di Gunung Tugel inidilakukan dengan tiga tahapan. Tahapan pertama adalah investigasi lapangan untukmengetahui kondisi lokasi dan dimensi longsor serta mengambil sampel tanah di lapangan.Tahap kedua adalah melakukan pengujian parameter tanah dan analisis data yang diperolehdari lapangan. Tahapan yang terakhir adalah analisis penanggulangan longsor denganmenggunakan data yang diperoleh dari tahapan sebelumnya. Pada penelitan ini, akanditerapkan tiga variasi perkuatan lereng yaitu dinding penahan tanah (DPT), turap dan DPTyang dikombinasikan dengan pondasi tiang. Analisis stabilitas lereng dilakukan dengan metodekeseimbangan batas. Berdasarkan hasil analisis yang dilakukan terhadap ketiga variasiperkuatan, DPT dengan kombinasi tiang pancang lebih direkomendasikan. Penerapan DPTyang dikombinasikan dengan minipile merupakan pilihan yang paling realistis denganpertimbangan tingkat kemudahan pelaksanaan di lapangan. Dari perhitungan yang telahdilakukan, untuk mencapai kondisi stabil diperlukan DPT dengan dimensi tinggi 2 meterdengan lebar bawah 2,5 meter. DPT tersebut ditopang oleh dua tiang tiap penampangmelintang dengan diameter 0,3 meter sepanjang 10 meter dengan jarak antar tiang 1 meter.kata kunci: tanah longsor, perkuatan tanah, metode keseimbangan batas


Author(s):  
Erwin G. Zoetendal ◽  
Antoon D. L. Akkermans ◽  
Wilma M. Akkermans-van Vliet ◽  
J. Arjan G. M. De Visser ◽  
Willem M. De Vos

2020 ◽  
Vol 13 (11) ◽  
pp. 1
Author(s):  
A. R. B. Zanco ◽  
A. Ferreira ◽  
G. C. M. Berber ◽  
E. N. Gonzaga ◽  
D. C. C. Sabino

The different integrated production systems can directly interfere with its bacterial community. The present study aimed to assess density, bacterial diversity and the influence of dry and rainy season in different integrated and an exclusive production system. The fallow and a native forest area was assessed to. Samples were collected in 2012 March and September. The isolation were carried out into Petri dishes containing DYGS medium. The number of colony forming units (CFU) was counted after 48 hours and. The bacterial density ranged between 106 and 107 CFU g-1 soil. The crop system affected the dynamics of the bacterial community only in the rainy season. The rainy season showed greater density of total bacteria when compared to the dry period regardless of the cropping system. The dendrograms with 80 % similarity showed thirteen and fourteen groups in the rainy and dry seasons. Isolates with the capacity to solubilize phosphate in vitro were obtained from all areas in the two seasons, but this feature has been prevalent in bacteria isolated during the rainy season


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