Using Anaerobic Bacteria in the Elimination of Plant Pathogens

By: Erik Zamarripa

Figure 1. This figure shows the changes in fungal cells during the co-incubation of pathogen Fusarium oxysporum. A. Shows intact cells on a PDA plate before adding pathogen. B. Shows changes after co-incubation for 3 days. C. Changes after co-incubation for 7 days.

There are many soil-borne pathogens that can affect the plants that are used for agriculture. For example Fusarium is a pathogen that causes spinach to wilt. Traditionally chemical fumigants such as methyl bromide and ethylene bromide would be used to chemically treat the soil for these pathogens however these have recently been restricted due to their harmful influence to atmospheric ozone and human health. Biological soil disinfestation (BSD) is the alternate process that is being looked into in order to eliminate soil-borne plant pathogens. This is a technique used to suppress plant pathogens but stimulating native microbes in the soil with the addition of organic materials. The technique is only four steps which are adding easily degradable carbon sources, irrigation of the soil to saturation, covering the soil with plastic for three weeks ( stimulates anaerobic bacteria), and finally removing plastic and planting crops. It is the stimulation of the anaerobic bacteria that causes the low survival of many plant pathogens. They create anoxic soil conditions that damage or kill aerobic pathogens and may even release antagonistic substances for soil pathogens. It is crucial to continue research into more environmentally friendly ways of dealing with plant pathogens for continued success of the agriculture production. However, these new techniques must also be efficient and effective but using anaerobic bacteria to combat soil-borne plant pathogens is a good step in that direction.

Original Article:
Atsuko U, Nobuo K, Katsuji U. (2018). Role of anaerobic bacteria in biological soil disinfestation for elimination of soil-borne plant pathogens in agriculture. ProQuest. https://search-proquest-com.tamiu.idm.oclc.org/docview/2048628616.

Microbial Communities vs. Deforestation

By: Laura Murillo

Figure 1. Abundances of major microbial populations in forest and pasture soils. Figure taken from Khan et al. 2019.

The Amazon forest has been a focal point in news lately, mainly because of the wildfires that 

have broken out, but this is not the only event affecting the vast ecosystem that is housed by

the Amazon. Due to rising human needs, such as fuel and food, deforestation has been 

inevitable.  And just like the bigger species, microorganisms are also affected. In order to see 

to what extent they are affected, Khan, Bohannan, and colleagues gathered a total of 10 soil

samples from a primary forest and an established pasture. Various instruments for extracting 

and sequencing DNA were then used to categorize and estimate the populations of the different microorganisms in both the forest and pasture. After their gathering data and analyzing the 

statistics, it was determined that the distribution of major microbial phyla between forest and pasture components was not preserved. We determined that microbial communities comprising the networks 

were significantly different between forest and pasture. These differences were true at the phylum 

(Khan et al., 2019). By looking at figure 3, acidobacteria and alphaproteobacteria were the ones with the greatest difference. This research really shows how much we really are taking a 

toll on our planet, and how even the smallest microorganisms are being affected. 

Original Article:

M A Wadud Khan, Brendan J M Bohannan, Klaus Nüsslein, James M Tiedje, Susannah G Tringe, Eloi Parlade, Albert Barberán, 

Jorge L M Rodrigues, Deforestation impacts network co-occurrence patterns of microbial communities in Amazon soils, FEMS Microbiology Ecology, Volume 95, Issue 2, February 2019. 

Staphylococcus aureus bacteria going extinct

Friday, September 20,2019

Staphylococcus aureus bacteria going extinct?

By: Marco V. Munoz

Fig. 1. Time trend for percentage of nosocomial methicillin resistant Staphylococcus aureus (MRSA) infections

Microorganisms are found pretty much everywhere, even in areas where most people think they are safe. Staphylococcus aureus is a gram-positive methicillin-resistant bacteria, commonly found in health-care facilities. This bacterium is responsible for many different sites of infections to humans, also known as nosocomial infection- given such name because the infection is obtained in hospitals. A prospective analysis carried by Kramer and colleagues demonstrated a significant reduction of four different infections linked to methicillin-resistant Staphylococcus aureus (MRSA) over 10 years in Germany. The Data from the infection sites included bloodstreams infections, lower respiratory tract infections, surgical site infections, and urinary tract infections.This is important to humans because resistance bacteria to antibiotics such as the one mentioned are the cause of morbidity and mortality all over the world. Although methicillin-resistant Staphylococcus aureus is not completely eradicated, the effort and precautions coming from the communities and health-care facilities together are the main keys for the soon coming to an extinct bacteria. 

Original Article.

Kramer TS , Schröder C , Behnke M , Aghdassi SJ , Geffers C , Gastmeier P , Remschmidt C. (2019). Decrease of methicillin resistance in Staphylococcus aureus in nosocomial infections in Germany-a prospective analysis over 10 years. The Journal of infection 78(3): 215-219.

The Correlation of Food Production with Climate Change

Figure 1. Map of orchards in northwestern Romania.

In the last two decades, earth has significantly seen an increase in climate change at a much faster rate, than that of previous deceniums all together. However, as prevalent as this subject is, most individuals do not apply any thought into it until they realize the harm. In a study by Gitea and colleagues, orchards located in northwestern Romania with fruits such as apples, plums and almonds are studied to find the correlation of the fruit production with climate change (figure 1). These fruit plants were studied in the period of 2002 to 2016 to observe their pre-blooming, blooming and ripening stages. These plants were observed and measured, in their blooming period to determine the amount of fruits they would produce. Then, in the summer of every year, it was noted when each fruit plant would begin to ripen until maturation ended. All plants were treated in the same manner with the same soil and with phytosanitary treatments in their optimum growth period. Statistical analyses were conducted using SPSS 19 and specific tests to determine the overall results. It was concluded that climate change affects the life cycle of these fruit plants. According to the results, the tree vegetation period started too early in the spring and the blooming periods of the plants were advanced by ten days which would ultimately slowly decrease the production of fruits over a period of time. 

Original article: Gitea, Manuel Alexandru, et al. “Orchard Management under the Effects of Climate Change: Implications for Apple, Plum, and Almond Growing.” Environmental Science and Pollution Research, vol. 26, no. 10, Sept. 2019, pp. 9908–9915., doi:10.1007/s11356-019-04214-1.

Metal Swims!

While some people don't think about where the waste of many things are dumped, many don't pay attention until it is too late. It can have an effect on ourselves, and the environment around us. As they continue to dump things into the water, whether they take in to the consideration the contamination they may cause or not. Some lakes have been showing results of contamination in some fishes that are common in those lakes. The fishes tissues were examined in order to find the results. The lakes in which this research was done are located in Canada. The fish were found to have higher concentrations of metal in their tissues, and while the metal concentrations dropped from 2004 to 2005, they still resulted in high concentration levels. Overall, it shows how much contamination there is, and how well we need to conserve the environment around us. We can plan a safe way of properly storing the waste we have.

Figure 1.  Inter-annual differences in PC and diet metal concentrations between 2004 and 2005.

Gauthier C􏰂, Campbell P. G. C., Couture P., (2009) Condition and pyloric caeca as indicators of food web effects in fish living in metal-contaminated lakes. Ecotoxicology and Environmental Safety 72 2066-2074. (2009).

LIKE SITTING DUCKS...IN THE MIDDLE OF ANTIBIOTIC RESISTANT MICROBIAL WATERS.

By: Alonso Trevino IV

While large bodies of freshwater only accounts for about 0.3% of the world’s entire freshwater sources, in retrospect they have for centuries proved to be vital sources of drinking water and entertainment. Whether the reason is to consume or simply enjoy, an increasingly hazardous situation has been simmering in these great lakes and rivers. Due to the ease by which human interaction disrupts the natural flow of these bodies of water (by way of pollution and sewage disposal) new developments seem to indicate the increase in antibiotic-resistant microbial organisms within the waters, bacteria which is consequently making its way into the mainstream, so to speak. Escherichia coli, Enterobacter spp., Klebsiella spp., Salmonella spp., Pseudomonas aeruginosa, Vibrio parahemolyticus, Aeromonas hydrophila, are some of the organisms, to name a few, that have recently begun to mutate into potentially more harmful micro bacteria. This conamtination mainly caused by animal and human fecal matter has made this an issue difficult to control and in the span of a few years, this issue has grown due to hormones used in animal feed and hospital waste. These organisms are known to be opportunistic pathogens. Some were found to be resistant to beta-lactam antibiotics like ampicillin and other antibiotics used commonly in any setting, other organisms were even found to resist a multitude of drugs. Meanwhile, we are sitting ducks in a world that continues to change for the worse, it is crucial that some regenerative plan begin before it is too late.

Figure 1. As seen in the above graph, the frequency of bacterial resistance to an antibiotic is very high which in turn, can affect not only therapeutic medical interventions but make it easier for certain bacteria’s to be contracted. The graph reveals that plasmid transfer is a very high possibility, a possibility which can quickly and more easily attack human cells.

Original Article:

Mudaliar, N., Kanojia, N., Shaikh, K., & Rathod, S. (2019). DETECTION OF DRUG RESISTANT ORGANISMS FROM NATURAL WATER BODIES