Number Of Psychrophilic Bacteria Research Articles

Indoor air Quality in Offices and Classrooms in Public Utility Building - A Case Study

A microbiological analysis of indoor air quality in offices, lecture rooms, and hallways in a public utility building has been carried out in the Lubuskie Voivodship (Poland). In one of the storage rooms, the presence of fungi on the building partition was found in the place of water infiltration as a result of a technological failure in the building. A total of 17 non-residential interiors were examined. The total number of psychrophilic and mesophilic bacteria and the total number of fungi were sampled by the collision method with the air sampler. A qualitative analysis has been performed of fungi present in the indoor air and from building partition of the studied interiors. A total of 11 species of fungi have been specified. Relative humidity and air temperature were measured with a hygrometer. The studies showed that the number of psychrophilic bacteria in indoor air was in the range 0–730 CFU/m<sup>3</sup>, while the number of mesophilic bacteria was slightly higher (0 - 896 CFU/m<sup>3</sup>). A high level of contamination and a large number of fungi (734 CFU/m<sup>3</sup>) were found in the indoor air of storage room, where the problem of biodeterioration of building partitions occurred. In the remaining rooms, the level of microorganisms was low or moderate. Microbiological tests of the outdoor air (background) did not reveal an excessive number of microorganisms in the air.

Effects of Turmeric, Cinnamon, and Lemon Extracts on Shelf Life, Nutrients, and Preservation of Carp Fish in Cold Storage

The present study aimed to investigate the effect of extracts of turmeric, cinnamon, and lemon on shelf life, macronutrients, and oxidative spoilage of the carp fish in cold storage at 4°C. Fishes were divided into five groups: control (NT); immersed fish in extracts of cinnamon, turmeric, and lemon (CTL); immersed fish in extracts of lemon and turmeric (LT); immersed fish in extracts of cinnamon and turmeric (CT); and immersed fish in extracts of lemon and cinnamon (LC). Results showed immersion of the carp fillet in extracts of turmeric, cinnamon, and lemon improved spoilage indices such as thiobarbituric acid, volatile nitrogen bases, and pH. The used extracts maintained the nutritional value and increased the fish’s shelf life. The compounds existed in the studied extracts decreased the values of the spoilage indices during cold storage. The highest spoilage indices were found for CL and CT treatments, and the lowest was for CTL treatment. The total bacterial load as well as the number of psychrophilic bacteria in the fish fillet found a significant decrease compared to the NT. Therefore, the best treatment was CTL, and inappropriate treatments were CT and CL. The fish shelf life for nine days was extended with the used extracts because the total count of cryophilic bacteria was 0.41 × 104 ± 0.50, which was the lowest compared to other treatments.

Physicochemical and microbiological quality of rainwater harvested in underground retention tanks

A study was made of the physicochemical properties (among others: pH, temperature, conductivity, hardness, chlorides, dissolved oxygen, ammonia, nitrites, nitrates, manganese, iron) and microbiological quality (coliform, psychrophilic and mesophilic microorganisms) of rainwater harvested from the roofs of three large buildings and from a parking lot, stored in three large underground tanks (with storage volume from 60 m3 to ca. 200 m3), including the variability of the quality. The underground tanks were located in the city of Poznań, and were characterized by different parameters, rainwater sources, rainwater treatment processes, and types of rainwater use. Samples of rainwater harvested in these tanks were collected from March 2019 to February 2020. Physicochemical and microbiological laboratory analyses were performed to determine selected parameters which have an impact on potential treatment and disinfection methods. The results obtained underwent statistical analysis. The laboratory tests showed that the physicochemical quality of rainwater collected in the three underground tanks met the Polish and EU requirements for drinking water standards. The main problem concerns microbiological quality: the number of coliform bacteria reached a value of 19,300 CFU/100 mL, the number of psychrophilic bacteria was over 264,000 CFU/1 mL, and the number of mesophilic bacteria was over 100,000 CFU/1 mL. Also the variability of microbiological quality was very high for all tanks. Analysis of the calcium carbonate equilibrium showed that the harvested water had corrosive properties. The treatment of the investigated rainwater for potable purposes should focus mainly on biological and chemical stability.

Effects of Vietnamese tamarind fish sauce enriched with iron and zinc on green mussel quality

Marinating is a traditional technology to improve the shelf - life and quality of products. Enriched Viet- namese tamarind fish sauce was prepared and used to marinate green mussels. Subjects of this research were: green mussels (C1), marinated green mussels (C2), and marinated green mussels packaged in modified atmosphere (M1, M2, and M3). A percentage of O :CO :N was 5:50:45 for M1, 5:70:25 for M2, and 5:90:5 for M3. Microbiological, hemical, and sensory qualities of the samples were analyzed during storage at 4°C for 30 days. The results indicate
 that glycogen, iron, and zinc contents as well as pH values decreased in all the cases during storage. In addition, TVB-N and TBARS values as well as mesophilic and lactic acid bacteria increased with time in all the samples. The number of psychrophilic bacteria in marinated samples was small or not detected at all. Escherichia coli, Staphylo- coccus aureus, Salmonella spp. and Vibrio cholera were below standard values. Based on sensory acceptability, the shelf-life of C1, C2, M1, M2, and M3 samples was 12, 18, 24, 24, and 27 days, respectively.

Potential effects of microbial air quality on the number of new cases of diabetes type 1 in children in two regions of Poland: a pilot study.

Aim: The aim of the study was to investigate the relationship between the concentration of psychrophilic bacteria, mesophilic bacteria and mold fungi in bioaerosols, and the number of new cases of type 1 diabetes mellitus (T1DM) in children.Methods: Air samples from the Lubelskie and Pomeranian voivodeships in Poland were collected from January 2015 to December 2016 in winter, spring, summer and autumn. Thirty-three samples were collected in the Pomeranian and 27 in the Lubelskie voivodeship. The air samples were collected on the first day of each month at 1:00 pm for 10 mins at a height of 1.5 m above the ground. The number of mesophilic bacteria was detected after 24–48 hrs incubation at 37°C on tryptone soya agar (TSA; Merck, Darmstadt, Germany). The number of psychrophilic bacteria was detected after 72 hrs incubation at 22°C on TSA. The number of fungi was detected by a 5-day long incubation at 28°C on chloramphenicol yeast glucose agar.Results: In the Lubelskie voivodeship, the mean concentration of psychrophilic bacteria was significantly higher than in the Pomeranian voivodeship (2739 vs 608 CFU/m3, respectively), the mean concentration of mesophilic bacteria was significantly higher (2493 vs 778/m3, respectively) and the concentration of fungi was significantly higher (3840 vs 688 CFU/m3, respectively). We also showed a statistically significant relationship between the number of children with recently diagnosed T1DM and the mean concentration of psychrophilic and mesophilic bacteria in the Pomeranian and Lubelskie voivodeships (P<0.001). Moreover, we found a significant relationship between the number of new cases of T1DM in children and the mean concentration of fungi in bioaerosols in the Lubelskie voivodeship (P<0.001), but not in the Pomeranian voivodeship (P=NS).Conclusion: The results of our research showed that there is a higher concentration of microbial particles in the Lublin voivodeship. Therefore, we recommend changes in climate for children (trips to the sea, mountains, etc) as often as possible.

Microbiological changes in the environment caused by deep dredging. A case study: post-dredging pit Kuźnica II (Puck Bay)

Abstract In this study psychrophilic, mesophilic and denitrifying bacterial abundances were studied seasonally (summer, autumn, winter and spring) in the water column and surface sediment layer (0-5 cm) in the post dredging pit Kuźnica II and natural areas of Puck Bay. The research was conducted between VI 2001 and III 2003. In the pit area an increase in mesophilic bacteria and a decrease in denitrifying bacteria numbers were observed, when compared to the natural areas. In the case of the mesophilic bacteria, the increase was visible in the near-bottom waters and surficial sediments during the period of well developed vegetation - in summer and autumn. In the case of denitrifying bacteria, the decrease of number concerned the sediments. Numbers of psychrophilic bacteria in both the natural and dredged areas did not differ significantly over the course of the study. These results suggest that deep dredging can cause the self-purification potential of the ecosystem to be diminished and induce strong bacteriological pollution.