In situ accessibility of Escherichia coli 23S rRNA to fluorescently labeled oligonucleotide probes

One of the main causes of failure of fluorescence in situ hybridization with rRNA-targeted oligonucleotides, besides low cellular ribosome content and impermeability of cell walls, is the inaccessibility of probe target sites due to higher-order structure of the ribosome. Analogous to a study on the 16S rRNA (B. M. Fuchs, G. Wallner, W. Beisker, I. Schwippl, W. Ludwig, and R. Amann, Appl. Environ. Microbiol. 64:4973–4982, 1998), the accessibility of the 23S rRNA of Escherichia coli DSM 30083T was studied in detail with a set of 184 CY3-labeled oligonucleotide probes. The probe-conferred fluorescence was quantified flow cytometrically. The brightest signal resulted from probe 23S-2018, complementary to positions 2018 to 2035. The distribution of probe-conferred cell fluorescence in six arbitrarily set brightness classes (classes I to VI, 100 to 81%, 80 to 61%, 60 to 41%, 40 to 21%, 20 to 6%, and 5 to 0% of the brightness of 23S-2018, respectively) was as follows: class I, 3%; class II, 21%; class III, 35%; class IV, 18%; class V, 16%; and class VI, 7%. A fine-resolution analysis of selected areas confirmed steep changes in accessibility on the 23S RNA to oligonucleotide probes. This is similar to the situation for the 16S rRNA. Indeed, no significant differences were found between the hybridization of oligonucleotide probes to 16S and 23S rRNA. Interestingly, indications were obtained of an effect of the type of fluorescent dye coupled to a probe on in situ accessibility. The results were translated into an accessibility map for the 23S rRNA ofE. coli, which may be extrapolated to other bacteria. Thereby, it may contribute to a better exploitation of the high potential of the 23S rRNA for identification of bacteria in the future

Effect of pH on electrochemical treatment using platinum coated titanium mesh electrodes for post treatment of anaerobically treated sugarcane vinasses

This study examines electrochemical post treatment to remove COD, SS, K+ and Cl- from anaerobically treated sugarcane molasses vinasse (ASMV). A platinum coated titanium mesh was used as an electrode material for both the cathode and anode, with 843.18 cm2 of working area. The effects of pH on removal efficiency, as well as energy and electrode consumption, were investigated. Influent ASMV was diluted 10 times and its initial pH was adjusted by addition of HCl and NaOH. The electrolysis experiment was performed at a current density of 94.88 A/m2 with 15 minutes of reaction time, and the effluent was collected after settling for 90 minutes. The results showed that the treatment efficiency was influenced by the initial pH value. A maximal COD removal efficiency (49.25%) was obtained at a pH of 5.0. For SS removal, the maximal efficiency (46.27%) was obtained at a pH of 10.0, and the lowest level of removal occurred at neutral pH conditions. The maximal efficiency of Cl- removal (17.59%) was obtained at a pH of 8.2 (non-adjusted), and its efficiency was lower when influent was adjusted to acidic and neutral pH conditions using HCl. Maximal efficiency of K+ removal (7.23%) occurred at neutral pH conditions and did not occur at alkaline pH values. Energy consumption was lower under pH-adjusted conditions than under non-adjusted conditions, and electrode consumption was higher in both acidic and alkaline conditions relative to neutral pH conditions

Use of G3-DHS Bioreactor for Secondary Treatment of Septic Tank Desludging Wastewater

Study was done for the use of the third-generation of downflow hanging sponge (G3-DHS) bioreactor for secondary treatment of septic tank desludging wastewater. The main objective of this study was to evaluate the prospective system of G3-DHS bioreactor to be applied in Indonesia. During experiment, the G3-DHS bioreactor kept a relatively high dissolved oxygen concentration under natural aeration. At a relatively short hydraulic retention (HRT) of 3 h, the G3-DHS bioreactor could remove up to 21% (SD = 15%) of total COD, 21% (SD = 7%) of filtered-COD, 58% (SD = 24%) of unfiltered-BOD, and 33% (SD = 24%) of ammonium removal. The final effluent had an unfiltered-BOD of only 46 mg/L (SD = 20 mg/L) that it was below the Indonesian standard (unfiltered-BOD = 100 mg/L) for thresholds of domestic wastewater treatment plants effluent

Unjuk Kerja Down-Flow Hanging Sponge (DHS) Bioreaktor sebagai Secondary Treatment untuk Pengolahan Limbah Domestik

Wastewater pollution will continue to grow as the population and community activities continue to increase. Various techniques have been applied for domestic waste treatment, but generally these processes require relatively high operation and maintenance costs. Down Flow Hanging Sponge (DHS) has been proposed as a solution to the problem of handling domestic waste for developing countries. DHS bioreactor is a biological waste treatment that does not require an aerator and is easy to operate. This study aims to evaluate DHS bioreactors that can be applied in Indonesia. DHS bioreactor is operated with 4 hours hydraulic retention time (HRT). The results showed that DHS bioreactor is able to reduce up to 34% Chemical Oxygen Demand (COD) total, 33% soluble Chemical Oxygen Demand (COD), 80% Biological Oxygen Demand (BOD) total, and 65% Ammonia.ABSTRAK Pencemaran  air limbah akan terus bertambah dengan meningkatnya jumlah penduduk dan aktifitas masyarakat. Berbagai proses telah diaplikasikan untuk pengolahan limbah domestik, tetapi umumnya proses-proses tersebut membutuhkan biaya operasi dan perawatan yang relatif mahal. Downflow Hanging Sponge (DHS) telah diusulkan sebagai pemecahan persoalan penanganan limbah domestik untuk negara-negara berkembang. DHS bioreaktor adalah pengolahan limbah secara biologis yang  tidak membutuhkan aerator dan mudah dalam pengoperasian. Penelitian ini bertujuan untuk mengevaluasi bioreaktor DHS sehingga dapat diterapkan di Indonesia. Bioreakor DHS dioperasikan dengan hydraulic retention time (HRT) 4 jam. Hasil penelitian menunjukkan DHS bioreaktor mampu mengurangi  hingga 34% Chemical Oxygen Demand (COD) total, 33% soluble Chemical Oxygen Demand (COD), 80% Biological Oxygen Demand (BOD) total, dan 65%  ammonia

Hydrocarbonoclastic Alcanivorax Isolates Exhibit Different Physiological and Expression Responseston-dodecane

Autochthonous microorganisms inhabiting hydrocarbon polluted marine environments play a fundamental role in natural attenuation and constitute promising resources for bioremediation approaches. Alcanivorax spp. members are ubiquitous in contaminated surface waters and are the first to flourish on a wide range of alkanes after an oil-spill. Following oil contamination, a transient community of different Alcanivorax spp. develop, but whether they use a similar physiological, cellular and transcriptomic response to hydrocarbon substrates is unknown. In order to identify which cellular mechanisms are implicated in alkane degradation, we investigated the response of two isolates belonging to different Alcanivorax species, A. dieselolei KS 293 and A. borkumensis SK2 growing on n-dodecane (C12) or on pyruvate. Both strains were equally able to grow on C12 but they activated different strategies to exploit it as carbon and energy source. The membrane morphology and hydrophobicity of SK2 changed remarkably, from neat and hydrophilic on pyruvate to indented and hydrophobic on C12, while no changes were observed in KS 293. In addition, SK2 accumulated a massive amount of intracellular grains when growing on pyruvate, which might constitute a carbon reservoir. Furthermore, SK2 significantly decreased medium surface tension with respect to KS 293 when growing on C12, as a putative result of higher production of biosurfactants. The transcriptomic responses of the two isolates were also highly different. KS 293 changes were relatively balanced when growing on C12 with respect to pyruvate, giving almost the same amount of upregulated (28%), downregulated (37%) and equally regulated (36%) genes, while SK2 transcription was upregulated for most of the genes (81%) when growing on pyruvate when compared to C12. While both strains, having similar genomic background in genes related to hydrocarbon metabolism, retained the same capability to grow on C12, they nevertheless presented very different physiological, cellular and transcriptomic landscapes

Activities of decentralized domestic wastewater treatment in ASEAN countries (A Series of International Activity Reports in the Materials Cycles Division)

pdfThe National Institute for Environmental Studies as the implementing agency of "Policy Dialogue and Network Building of Multi-stakeholders on Integrated Decentralized Domestic Wastewater Management in ASEAN Countries” by utilizing the Japan-ASEAN Integrated Fund (JAIF) started in July 2018, have published a report booklet that briefly summarizes the current status of water environment and domestic wastewater management in 9 ASEAN countries who participated in the project, and activities related to the formation of a network of policy makers and experts to realize proper management. 政策提言では、令和2年12月末に終了した日・ASEAN統合基金（JAIF）の活用による「ASEAN加盟国における分散型生活排水処理の統合的管理に向けたマルチステークホルダーネットワーク形成と政策対話」（「JAIF-PoDIWM事業」）の活動に基づいた、事業実施にあたっての背景と目的を解説したうえで、分散型生活排水処理の導入に関する効果と利点を解説しています。日本型の浄化槽を含む分散型の技術システムの適切な管理においては、建設・導入時のルール整備だけでなく、定期的な点検・維持管理と、機能評価などの枠組み作りが必須であり、そのための行政機関や業界団体における人材育成の必要性についても言及したうえで、JAIF-PoDIWM事業に参加した東南アジア9か国の水環境・生活排水管理の現状に関する制度や技術上の現状と課題について概観しました。こうした東南アジア諸国の現状や特徴を考慮しつつ、持続可能な分散型生活排水処理システムを選択するための意思決定支援ツールを紹介しています。さらに、生活排水の適正管理に係る5つの提言と未来像を示すとともに、事業に参加した実務者ならびに研究者からの宣言を記載しました。boo

Development of simple and cost-effective treatment system for municipal wastewater

This study developed an alternative municipal sewage treatment system based on the pilot- and full-scale experiments. This proposed system consisting of upflow anaerobic sludge blanket (UASB) and trickling filter using a polyurethane sponge as packing material. This aerobic process was originally developed and named as a down-flow hanging sponge (DHS). DHS reactors accomplished high process performance during pilot- and full-scale experiments in Japan and other countries. The effluent quality of the DHS reactors was comparable to that of activated sludge systems. Moreover, advantages of DHS reactors include simple operation and maintenance (OM), no required oxygen supply, small land requirement, and less excess sludge production. Indeed, the estimated energy requirement and excess sludge production of UASB and DHS systems were found to be approximately 75 and 85 % lower than those of conventional activated sludge systems, respectively. The high process performance can be attributed to the fact that the DHS reactor maintains much of the sludge in the reactor at concentrations 510 times higher than activated sludge. This indicates that DHS reactors have the potential for use as reliable, affordable, and efficient treatment systems, and can be used widely including developing countries