Physicochemical and bacteriological screening of pathogenic microorganisms from aquarium water collected from katabon area in Dhaka city

Globally, the ornamental fish business has a high demand for its popularity as well as for its profitability. However, microbial contamination, nutrient depletion and accumulation of organic materials are the major factors in an aquafarming system which can cause death of aquatic animal and causes financial losses. This study aimed to determine the physicochemical and microbiological quality of fish aquarium water. Water of different time interval after treatment (7 days, 20 days, 30 days, 60 days, 90 days) were taken from the different aquariums. A set of physicochemical parameters such as temperature, transparency, pH, conductivity, dissolved oxygen, total dissolved solids, alkalinity, total hardness, conductivity were found within the approved standard concentration for fish. The present study also reveals the microbiological status of the aquaculture water where the total viable count ranging from 2.20×104 to 4.20×104 cfu/ml. Escherichia coli, Staphylococcus spp., and Pseudomonas spp. were present in all samples. Antimicrobial susceptibility tests were also done to determine the antibiotic resistance pattern of microbes isolated from aquarium water. Stamford Journal of Microbiology, Vol.11 (1) 2021: 20-23

Aquaculture Water Quality Improvement by Mixed Bacillus and Its Effects on Microbial Community Structure

Nutrients nitrogen and phosphorus pollution in aquaculture is one of the greatest challenges threatening the survival of aquatic organisms, which requires efficient and sustainable remediation approach. Microbial remediation, especially the application of probiotics, has recently gained popularity in improving the water quality and maintaining the health condition of aquatic animals. In the present study, two groups of mixed Bacillus (Bacillus megaterium and Bacillus subtilis (A0+BS) and Bacillus megaterium and Bacillus coagulans (A0+BC)) were applied to aquaculture system of Crucian carp to improve the treatment of nitrogenous and phosphorus compounds. The effects of mixed Bacillus on water quality, and the structure and function of microbial communities in aquaculture water were investigated. Our results showed that the improvement effect of mixed Bacillus A0+BS on water quality was better than that of A0+BC, and the NH4+-N, NO2--N, NO3--N and total phosphorus (TP) concentrations were reduced by 46.3%, 76.3%, 35.6%, and 80.3%, respectively. In addition, both groups of mixed Bacillus increased the diversity of bacterial community and decreased the diversity of fungal community. Microbial community analysis showed that mixed Bacillus A0+BS increased the relative abundance of bacteria related with nitrogen and phosphorus removal, e.g., Proteobacteria, Actinobacteria, Comamonas, and Stenotrophomonas, but decreased the relative abundance of pathogenic bacteria (Acinetobacter and Pseudomonas) and fungi (Epicoccum and Fusarium). The redundancy analysis showed that NH4+-N, NO2--N, and TP were primary environmental factors affecting the microbial community in aquaculture water. PICRUST analysis indicated that all functional pathways in the treatment groups were up-regulated, and all pathways in A0+BS group were richer than those in other groups. These results indicated that mixed Bacillus A0+BS addition produced good results in reducing nitrogenous and phosphorus compounds and shaped a favorable microbial community structure to further improve water quality.

A Review of Ammonia-Oxidizing Archaea and Anaerobic Ammonia-Oxidizing Bacteria in the Aquaculture Pond Environment in China

The excessive ammonia produced in pond aquaculture processes cannot be ignored. In this review, we present the distribution and diversity of ammonia-oxidizing archaea (AOA) and anaerobic ammonia-oxidizing bacteria (AnAOB) in the pond environment. Combined with environmental conditions, we analyze the advantages of AOA and AnAOB in aquaculture water treatment and discuss the current situation of pond water treatment engineering involving these microbes. AOA and AnAOB play an important role in the nitrogen removal process of aquaculture pond water, especially in seasonal low temperatures and anoxic sediment layers. Finally, we prospect the application of bioreactors to purify pond aquaculture water using AOA and AnAOB, in autotrophic nitrogen removal, which can reduce the production of greenhouse gases (such as nitrous oxide) and is conducive to the development of environmentally sustainable pond aquaculture.

Sphingobacterium micropteri sp. nov. and Sphingobacterium litopenaei sp. nov., isolated from aquaculture water

Two novel bacterial strains, designated as DN00404T and DN04309T, were isolated from aquaculture water and characterized by using a polyphasic taxonomic approach. Cells of strains DN00404T and DN04309T were Gram-stain-negative, aerobic, non-motile, oxidase-positive and catalase-positive. Cells of DN00404T were short rod-shaped and those of DN04309T were long rod-shaped. Strain DN00404T was found to grow at 15–37 °C (optimum, 25–30 °C), at pH 6.0–11.0 (optimum, pH 7.5) and in 0–2.0 % (w/v) NaCl (optimum, 1.0 %). Strain DN04309T was found to grow at 15–45 °C (optimum, 20–37 °C), at pH 5.5–11.0 (optimum, 7.5) and in 0–4.0 % (w/v) NaCl (optimum, 0.5 %). Phylogenetic analyses based on 16S rRNA gene and genome sequences revealed that the two strains belonged to the genus Sphingobacterium and were distinct from all known species of this genus. The average nucleotide identity (ANI) and digital DNA–DNA hybridization (dDDH) values between the two strains and between each of the two strains and related type strains of this genus were well below the recognized thresholds of 95.0–96.0 % ANI and 70.0 % dDDH for species delineation. The genomic DNA G+C contents of strains DN00404T and DN04309T were 41.6 and 36.0 mol%, respectively. The respiratory quinone in both strains was identified as MK-7, and their major fatty acids were iso-C15 : 0 and summed feature 3 (C16 : 1 ω6c and/or C16 : 1 ω7c), which were similar to those of other species of this genus. The two major fatty acids C16 : 0 and iso-C17 : 0 3-OH were also found in strain DN00404T. Based on genotypic and phenotypic characteristics, two novel species of the genus Sphingobacterium are proposed: Sphingobacterium micropteri sp. nov. with DN00404T (=GDMCC 1.1865T=KACC 21924T) as the type strain and Sphingobacterium litopenaei sp. nov. with DN04309T (=GDMCC 1.1984T=KCTC 82348T) as the type strain.

Development of aquaculture water quality real-time monitoring using multi-sensory system and internet of things

Water quality is an important parameter for the health and growth of aquatic species in aquaculture farming system. The threshold values of the water main parameters should be monitored continuously. Contaminated aquaculture water will affect the health, growth and ability of animals to survive. In addition, it will also affect the harvesting yields based on the number and size of the animals. To overcome this problem, the main water parameters, namely temperature, pH, Dissolved Oxygen and Electrical Conductivity are monitored in real-time using a multi-sensory system and the internet of things. Data is acquired by a developed instrument and transmitted wirelessly via a GPRS / GSM module to a web server database. The data obtained are analyzed and monitored through the website and in real-time. Therefore, corrective action could be taken immediately for contaminated water, indicated by water parameters out of range. The system also provides an early signal to farmers based on a specific range of water quality parameters values. This will help farmers make adjustments to ensure appropriate water quality for the aquaculture system.

Automatic River Water Quality Monitoring Using IOT

One of the major problems in India is surface water pollution that is in Rivers. For the purpose of drinking, agriculture requirements and for industrial usage, an adequate amount of water quality has to be made sure and for maintaining the balance in aquaculture, water quality has to be monitored in real time. Deteriorated quality of water affects all well living beings. Traditional River water quality monitoring involves grab sampling, testing and analysis which is time consuming. In this project, determined attempts are made to design an economical system for real time monitoring of river water quality. Different physical and chemical parameters of the water are monitored using various water measuring sensor. The parameters such as temperature, hardness, dissolved oxygen; pH, turbidity and flow can be measured through sensors. The system can be enforced with Arduino model as a core controller. WI-FI module, Internet of things and GSM board can be used effectively to monitor the water quality and thereby relevant impacts for using river water safely. Keywords: 1. IOT, 2. GSM, 3. Sensors, 4. E.C.