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Actinobacterial Communities of Chosen Extreme Habitats in China

Jia Pengli, Li Miao, Feng Haiyan, Ma Mutian, Gai Jingping, Yang Zhongfang

Polish Journal of Ecology

2020

Vol. 68, nr 3

181--194

Actinobacteria living in frozen soils which potentially could be producers of valuable and biologically active metabolites, remain still largely unexplored. Therefore, the diversity of culturable actinobacteria in the six frozen soil samples collected from the high-latitude and the high-altitude regions in China was investigated by using the culture-dependent method and 16S rRNA gene analysis. A total of 184 culturable actinobacterial isolates (morphotypes) were obtained. The abundance of culturable actinobacteria was 6.20 × 103–3.49 × 105 colony forming units (CFU) per gram of soil (dry weight). The actinobacteria isolated from the high-latitude region in China belong to five genera: Streptacidiphilus, Kitasatospora, Streptomyces, Arthrobacter, and Rhodococcus. The strains belonging to Arthrobacter were dominant, the 19 strains were closely related to Arthrobacter globiformis in terms of evolutionary distance. The actinobacterial isolates from the high-altitude region, from 2,813 m to 4,775 m in elevation, in China could be grouped into six genera (Arthrobacter, Microbacterium, Streptomyces, Rhodococcus, Nocardia, and Nocardiopsis), with dominant Streptomyces and Arthrobacter strains. The 4 strains were closely related to Rhodococcus fascians and one strain was closely with Microbacterium hydrocarbonoxydans in terms of evolutionary distance. Three genera of Arthrobacter, Streptomyces, and Rhodococcus were found in both areas. Our research provides new insight into the characteristics of the distribution of actinobacteria associated with frozen soils, which help us gain a better understanding of the potential of the cryogenic environments – the potential source of actinobacterial antibiotics.

The microbial response to the organic and natural fertilisers under maize grown for silage in monoculture

Niewiadomska A., Sulewska H., Ratajczak K., Wolna-Maruwka A., Waraczewska Z.

Journal of Research and Applications in Agricultural Engineering

2017

Vol. 62, nr 4

33--40

The aim of the study was to assess the influence of organic and natural fertilisation under maize plantation grown in monoculture on the number of selected groups of microorganisms. The experiment was conducted between 2005 and 2007 in plots of the Experimental and Educational Station in Swadzim, Department of Agronomy, Poznań University of Life Sciences, Poland. Soil taken from maize for silage was the research material. Soil samples for microbiological analyses were collected at a particular phase of maize development: before sowing; at the phase of maize emergence (BBCH 11-13); at the phase of 3-4 maize leaves (BBCH 13-14), at the phase of 6-7 maize leaves (BBCH 16-17), at the phase of panicle florescence (BBCH 63-69), at the phase of wax maturity (BBCH 87-89). The number of selected groups of microorganisms in the soil samples (moulds, total bacterial count, proteolytic and ammonifying bacteria, copiotrophs, oligotrophs and actinobacteria) was measured with the pour plate method developed by Koch. Between 2005 and 2007 natural and organic fertilisation in plots with a maize monoculture grown for silage increased the intensity of proliferation in all the groups of microorganisms under study. The trend and rate of variation in the microorganisms depended on the type of organic matter applied to soil and the term of analyses related with the plants’ stage of development.

Celem pracy była ocena wpływu nawożenia organicznego i naturalnego w uprawie kukurydzy, w monokulturze na liczebność wybranych grup mikroorganizmów. Doświadczenie prowadzono na poletkach Zakładu Doświadczalno-Dydaktycznego w Swadzimiu, należącym do Katedry Agronomii, Uniwersytetu Przyrodniczego w Poznaniu, w latach 2005-2007. Gleba pobrana spod kukurydzy przeznaczonej na kiszonkę była przedmiotem badań. Gleba pobrana spod kukurydzy przeznaczonej na kiszonkę, była przedmiotem badań. Próbki glebowe do analiz mikrobiologicznych pobierane były w określonej fazie rozwojowej kukurydzy: przed siewem; w fazie wschodów kukurydzy (BBCH 11 - 13); w fazie 3 - 4 liści kukurydzy (BBCH 13 - 14), w fazie 6 - 7 liści kukurydzy (BBCH 16 - 17), w fazie kwitnienia wiech (BBCH 63 - 69), w fazie dojrzałości woskowej (BBCH 87 - 89). W pobranych próbach glebowych oznaczano liczebność wybranych grup drobnoustrojów (grzyby pleśniowe, ogólna liczba bakterii, bakterie proteolityczne i amonifikacyjne, kopiotrofy, oligotrofy i promieniowce) metodą płytek lanych według Kocha. W przeprowadzonych badaniach, w latach 2005-2007 nawożenie naturalne i organiczne na stanowiskach z monokulturą kukurydzy uprawianej na kiszonkę przyczyniło się do wzrostu intensywności namnażania wszystkich badanych grup drobnoustrojów. Kierunek i tempo zmian mikroorganizmów zależały od rodzaju materii organicznej trafiającej do gleby oraz terminu analiz związanego z fazą rozwojową rośliny.

Wpływ wybranych metali ciężkich na wzrost i namnażanie promieniowców z rodzaju Streptomyces izolowanych z gleb

Lenart-Boroń A, Boroń P, Banach T

Inżynieria i Ochrona Środowiska

2013

T. 16, nr 1

81--91

Mając na uwadze wzrost zanieczyszczenia środowiska naturalnego metalami ciężkimi i ich oddziaływanie na mikroorganizmy w glebie, podjęto próbę określenia wpływu wybranych metali ciężkich: miedzi, kadmu, cynku i ołowiu na wzrost promieniowców wyizolowanych z gleb pobranych z terenu huty ArcelorMittal w Krakowie. Do badań wykorzystano 5 gleb, z których do dalszych badań wyselekcjonowano 10 izolatów promieniowców należących do rodzaju Streptomyces. Przeprowadzone analizy wykazały, że obecność huty przyczynia się do zanieczyszczenia środowiska glebowego poprzez emisje metali ciężkich. Ma to wpływ także na populację promieniowców w glebie nie tylko poprzez ograniczenie ich liczebności, lecz również poprzez selekcję szczepów opornych na zanieczyszczenia gleb, a przez to na ograniczenie ich bioróżnorodności. Pośrednim skutkiem ograniczenia różnorodności promieniowców może być wyginięcie szczepów ważnych pod względem funkcjonalnym dla środowiska, zubożenie mikroflory gleby, a także zmiany właściwości fizykochemicznych gleby. Niniejsza praca pokazuje, że skażenie środowiska metalami ciężkimi jest poważnym problemem środowiskowym. Zjawisko to należy monitorować i kontrolować, aby zapobiec nieodwracalnym zmianom w ekosystemie.

People have changed their environment since the beginning of the civilization - it is an inevitable process. However, this phenomenon is accompanied by emission of many harmful chemicals to the environment, and recently there has been an increase in the amount of pollution. Having regard to the increase in environmental contamination with heavy metals due to the expanding industry and its impact on soil microorganisms, this study attempted to determine the effect of the selected heavy metals: cadmium, copper, lead and zinc, on the growth of actinobacteria (belonging to the genus Streptomyces) isolated from soils of ArcelorMittal steelworks in Cracow. Five soil samples were selected for the analysis, from which 2 isolates of Streptomyces spp. were selected for further analyses. The number of Streptomyces spp. in the soil samples was determined using the serial dilutions method. The systematic affiliation of microorganisms was confirmed by macroscopic as well as microscopic observations of Gram-stained smears, catalase reaction test and the sequencing of 16S rDNA region. Additionally, soil physical and chemical properties were examined - pH, moisture and heavy metal content - using atomic spectrometry. The heavy metal resistance of the examined Streptomyces spp. strains was analyzed using a well method with increasing concentrations of cadmium, copper, lead and zinc. After the incubation results were recorded as the growth inhibition zones (diameters) and the minimum inhibitory concentration (MIC) of the heavy metals were determined. The conducted analyses revealed that heavy metal concentrations in two out of five examined soils exceeded the admissible values given by the Regulation of the Minister of Environment on soil quality standards. The number of actinobacteria in soils was varied (from 6700 to almost 250 thousand CFU per gram of soil dry weight). There was a negative correlation between the heavy metal concentrations in soils and the number of the studied microorganisms. The analyzed soils were alkaline - the lowest pH value was 7.7. Regarding the heavy metal resistance of the analyzed Streptomyces spp. strains, diverse in vitro susceptibility was recorded. The bacterial reactions differed even between strains isolated from the same soil samples. Minimum inhibitory concentrations of the examined heavy metals were as follows: Cd and Cu - 100 μg • cm−3, Zn - 3000 μg • cm−3 and Pb - 8000 μg • cm−3. There was a negative correlation between the concentration of heavy metals in soils and the growth inhibition zones (in the case of cadmium this correlation was high), indicating that the soil contamination with cadmium may have modified the soil population of Streptomyces spp., causing extinction of the susceptible strains while the ones with reduced sensitivity survived. The results of the presented research indicated that the ArcelorMittal steelworks contaminates the soil environment, which may affect the microbial community of soils, not only by reducing the population, but also by decreasing biodiversity of soil microorganisms, which was particularly visible in the case of cadmium - a strongly toxic heavy metal. This study demonstrates that the heavy metal contamination is a serious environmental problem. This phenomenon needs to be monitored and controlled to prevent irreversible changes to the ecosystem.