The analysis examines aerobiomes, timber, and public well being results
Environmental microorganisms play an essential role in human health – the more diverse the consortium, the better. The variety of microorganisms helps the immune system to react to pathogens.
It also helps control overstimulation of the immune system in response to harmless substances like dust particles, pollen, and sometimes our cells – the latter manifest as autoimmunity. It is known that exposure to these microbiomes from the environment in early childhood contributes to the development of strong immunity.
In addition to better immunity, the various microbiomes supplement humans with important functional microorganisms. It is found that soil-producing butyrate-producing bacteria can supplement the gut bacteria and reduce anxiety. Certain bacteria produce important molecules that are essential for human health: inhibit tumors and atherosclerosis, improve bone formation, promote epithelial integrity, etc. Exposure to plant diversity and associated microbial communities also correlates significantly with reduced risk of acute one lymphoblastic leukemia by promoting immune maturation.
Urbanization and the loss of macrobiodiversity are linked to the loss of microbial diversity, which can negatively impact the health-promoting microbial communities that live in and on human bodies – the human microbiome.
In a recent BioRxiv * preprint paper, Jake M. Robinson and colleagues examine the dynamics of the "aerobiome" – the collection of microorganisms in a given airspace in relation to height from the ground. Investigation of the dynamics of near-surface aerobiomes in urban green spaces is minimal. However, studies show that the aerobiomes differ in urban and semi-urban areas. They differ in urban green and gray spaces, are modulated by the type of vegetation and influenced by local changes such as weather or land management.
In an earlier study, the researchers demonstrated vertical stratification of the aerobiome between ground level and 2 m in an urban green space.
A person can be exposed to any type of aerobioma. The diversity and function of the aerobiome change depending on the habitat and altitude – and their interactions. Therefore, the effects of various aerobiomes can have implications for individual and public health.
This study focuses on aerobic bacterial communities. The team used an innovative columnar sampling method to study aerobic bacterial communities in three urban green space habitat types in the Adelaide Parklands, South Australia. Their goal was a careful comparison and assessment of the aerobiome diversity, vertical stratification, the influence of tree density and pathogenic bacterial taxa between the three habitats. The habitats include grasslands, forests / scrub (dominated by native Eucalyptus spp. Trees and shrubs; hereinafter referred to as "scrub") and bare soil habitat; Every living space is a typical urban green space.
Profile of the bacterial communities from each habitat at the phylum level. The colored area of each bar represents the relative abundance of the corresponding strain over 1%. The X-axis shows the sample heights: floor, 0.0 m, 0.5 m, 1.0 m and 2.0 m (from left to right). The photos above the plots show examples of each habitat used in the study (photos by authors).
They characterized the diversity, composition, and network complexity of aerobiomes by sequencing the bacterial next-generation 16S rRNA gene. The authors used geographic analysis methods to investigate the possible influence of trees on the microbiodiversity of aerobiomes.
They found the dominant bacterial community in all three habitats: Proteobacteria, Bacteroidetes and Actinobacteria. However, the frequency of the bacteria varied with altitude. They also found that the peeling aerobiome was more biologically diverse than the bare ground; In fact, it had the most biodiverse aerobiome.
The bacterial diversity on the bare ground is reduced to 2 m with increasing sampling height from the ground. The highest variety was at ground level.
The authors tested for diversity differences between data and locations and found no significance in considering them.
The results show that the aerobiome bacterial community differed significantly between the habitat types of urban green spaces. This study shows that aerobiome diversity, composition, and network complexity are layered vertically. This suggests that the potential exposure and transmission of bacteria depends on the type of habitat, as well as the size or behavior of the person.
The study suggests that urban habitats with more complex vegetation communities are more biologically diverse. Urban green spaces must have this vegetation to ensure exposure and transmission of bacteria from the environment to the skin and respiratory tract. Since these bacteria are essential for better health, urban planning must implement the vegetation spaces intelligently.
The results also confirm that trees and the larger canopy are associated with higher aerobiome diversity. The team found abundant suspected pathogenic taxa, the proportions of which were significantly different between grassland and bush habitat samples. Since only identifiable bacterial taxa were used in the different frequencies and analyzes, the authors suggest that further investigations are required here.
This study found that grassland had a significantly higher proportion of identifiable pathogenic bacteria compared to peeling. However, the frequency of the bacteria decreased significantly with the level of sampling.
According to the authors, individuals may be exposed to different aerobiomes on a human scale, depending on the type of habitat they visit and the altitude-related fluctuations in environmental aerobiomes. This is an important study that highlights where the priorities for better health, improved immunity, a diverse microbiome, green space restoration and defense against fast pathogenic microorganisms and urban space planning should be. Impact on landscape management and public health. In this direction, efforts are required to restore complex vegetation communities and host-microbiota interactions that play a multifunctional role in urban ecosystems.
* Important NOTE
bioRxiv publishes preliminary scientific reports that are not peer-reviewed and therefore should not be considered conclusive, guide clinical practice / health-related behavior, or be treated as established information.