Control Of Microbial Processes Research Articles

REVIEW OF MICROBIOLOGICAL ANALYSIS OF DRINKING WATER FOR ANIMALS IN THE REPUBLIC OF SRPSKA (BOSNIA AND HERZEGOVINA) DURING THE PERIOD 2018-2020.

One of the major challenges for all in the 21st century is safe drinking water and the microbiological control of drinking water should be the norm everywhere. Many infectious diseases of animals and humans are transmitted by water contaminated with human and animal excrements. The production and distribution of microbiologically safe drinking water should be a non-negotiable goal for water companies with the prospect of providing the same water quality to all consumers. This can only be achieved by adequate monitoring and control of microbial processes during water treatment and distribution. The material represented drinking water samples originating from animal farms at the territory of the Republic of Srpska (Bosnia and Herzegovina) collected in the period of 2018-2020. A total of 645 samples were examined. The aim of this study was to determine the microbiological status of drinking water for animals intended for human consumption in the Republic of Srpska (Bosnia and Herzegovina), in order to analyse the risks to animal health. BAS EN ISO 6222, BAS EN ISO 7899-2 and BAS EN ISO 9308-1/A1 methods were used for microbiological analyses of drinking water samples. The obtained results showed that one quarter of drinking water for animals are microbiologically incorrect. The analysis revealed a significantly higher number of unsatisfactory samples of well water in relation to the water supply system. The obtained results indicate fecal contamination of water, especially with intestinal enterococci and coliforms, and less with E. coli.

Quantifying microorganisms during biooxidation of arsenite and bioleaching of zinc sulfide

The development of molecular tools for the detection and quantification of both species as well as functional traits, aids in a better understanding and control of microbial processes. Presently, these methods can also be used to assess the activity of these organisms or functions, even in complex ecosystems and difficult matrices such as ores and low pH samples. In this paper we present the versatility of one of these tools, Q-PCR, to allow accurate and fast insight in changes in two types of microbial processes representing two ways in which microbes can interact with metals, bioleaching and bioprecipitation. Using the Q-PCR technique it was possible to identify and quantify the thermoacidophilic archaeon Acidianus sp. to be the main microbial strain responsible for biooxidation of arsenite in a low pH reactor. The method was also used to study the dynamics between the iron oxidizing and sulfur oxidizing acidophiles during bioleaching of a zinc concentrate in a batch reactor system and showed that the iron oxidizer Leptospirillum ferriphilum that dominated the starting culture disappeared upon addition of the concentrate. Gradually, bacterial activity was regained starting with growth of sulfur oxidizers and at later stage iron oxidizers started to grow. Molecular analysis can be used to direct research to the relevant organisms involved and concentrate on improving their application (in the arsenite case Acidianus sp.) or in understanding appearances and disappearances of microorganisms (during leaching of zinc concentrate the disappearance of Leptospirillum after high inoculation levels) in order to allow optimization of leaching efficiencies at the lowest (oxygen) costs.

Prerequisites for the on-line control of microbial processes by flow injection analysis

Problems associated with the use of biosensors in process control, e.g. difficulties of sterilization and sensor fouling, are shortly displayed, and possibilities to overcome them are outlined. The advantages of flow injection analysis (FIA) are demonstrated and examples for efficient sampling systems connected with this method are reviewed. Special emphasis is given to problem-orientated sample pretreatments, preventing fast inactivation of immobilized enzymes in the analysis system. Examples of problem-orientated sample pretreatment units are given. A proposal for a computer-controlled self-calibrating FIA system is given.

INTENTIONAL CONTROL OF GENE EXPRESSION BY TEMPERATURE USING THE REPRESSOR-PROMOTER SYSTEM OF BACTERIOPHAGE LAMBDA

We investigated a gene expression system which could be regulated by temperature manipulation to develop a biological tool for intentional control of microbial processes. For this purpose we used a...