scholarly journals Microbial Production of Polyhydroxy alkanoates (PHAs) using Kitchen Waste as an Inexpensive Carbon Source

2019 ◽  
Vol 16 (1) ◽  
pp. 155-166 ◽  
Author(s):  
Rayasam Vijay ◽  
Kumar Tarika

It is a well-known fact that Polyhydroxyalkanoates (PHAs) have the potential to replace petrochemical based plastics. The purpose of our study is to devise a method to reduce substrate cost and produce PHA from our own microbial isolates selected after isolation from polluted environments. A comparative study was done with the reference bacterium Cupriavidus necator. Fourteen bacterial strains were isolated from Polluted Landfills and Effluent Treatment Plant. Four bacterial isolates having the ability to produce PHA were selected. Orange peel and Onion peel were substituted for carbon source in the medium and all the bacterial isolates along with the reference strain were studied for the maximum ability to produce PHA from these wastes respectively. The reference strain Cupriavidus necator yielded 82% PHA in 1:1 C:N ratio utilizing onion peel and 64% in 4:1 C:N ratio utilizing orange peel at 96h of incubation respectively. The best results obtained on onion peels as carbon source were by the isolate Bacillus subtilis JCM 1465 with 89% in 3:1 at 48h of incubation. Maximum PHA production obtained by bacterial isolate Bacillus siamensis PD- A10 using orange peel as carbon source was upto 82% in 1:1 at 24h of incubation.

2016 ◽  
Vol 9 (1) ◽  
pp. 62-67 ◽  
Author(s):  
R. Jame ◽  
V. Zelená ◽  
B. Lakatoš ◽  
Ľ. Varečka

Abstract Five bacterial isolates were tested for their ability to generate hydrogen during anaerobic fermentation with various carbon sources. One isolate from sheep rumen was identified as Escherichia coli and four isolates belonged to Clostridium spp. Glucose, arabinose, ribose, xylose, lactose and cellobiose were used as carbon sources. Results showed that all bacterial strains could utilize these compounds, although the utilization of pentoses diminished growth yield. The excretion of monocarboxylic acids (acetate, propionate, formiate, butyrate) into medium was changed after replacing glucose by other carbon sources. Di- and tricarboxylic acids were excreted in negligible amounts only. Spectra of excreted carboxylic acids were unique for each strain and all carbon sources. All isolates produced H2 between 4—9 mmol·L−1 during the stationary phase of growth with glucose as energy source. This value was dramatically reduced when pentoses were used as carbon source. Lactose and cellobiose, starch and cellulose were suitable substrates for the H2 production in some but not all isolates. No H2 was produced by proteinaceous substrate, such as blood. Results show that both substrate utilization and physiological responses (growth, excretion of carboxylates, H2 production) are unique functions of each isolate.


2011 ◽  
Vol 8 (4) ◽  
pp. 1582-1587 ◽  
Author(s):  
M. Mohsen Nourouzi ◽  
T. G. Chuah ◽  
Thomas S. Y. Choong ◽  
C. J. Lim

Mixed bacteria from oil palm plantation soil (OPS) were isolated to investigate their ability to utilize glyphosate as carbon source. Results showed that approximately all of the glyphosate was converted to aminomethyl-phosphonic acid (AMPA) (99.5%). It is worthy to note that mixed bacteria were able to degrade only 2% of AMPA to further metabolites. Two bacterial strainsi.e. Stenotrophomonas maltophiliaandProvidencia alcalifacienswere obtained from enrichment culture. Bacterial isolates were cultured individually on glyphosate as a sole carbon source. It was observed that both isolates were able to convert glyphosate to AMPA.


Author(s):  
Viola Zaki ◽  
Ahmed EL-gamal ◽  
Yasmin Reyad

he present research carried out to study the common bacterial infections in Oreochromis niloticus (Nile tilapia) in Manzala area at Dakahlia governorate and possible antimicrobial agents used for treatment. A total number of 400 fish were randomly collected from Manzala private farms at Dakahlia governorate and subjected to the clinical, bacteriological and histopathological examination. The highest prevalence of bacterial isolates during the whole period of examination of naturally infected O.niloticus was recorded for A.hydrophila (22.66%), followed by V.alginolyticus (19.01%), V.parahemolyticus (13.80%), Streptococcus spp. (12.24%), A.caviae (11.72%), V.cholera (10.16%), A.salmonicida (7.55%), while the lowest prevalence was recorded for Klebsiella oxytoca (2.86%). The seasonal highest total prevalence of bacterial isolates from examined naturally infected O. niloticus was recorded in spring (30.21%), followed by autumn (28.39%), then summer (22.40%) and the lowest prevalence was recorded in winter (19.01%). Histopathological findings of the tissue samples which collected from different organs of naturally infected O.niloticus revealed that spleen show marked hemosiderosis and sever hemorrhage, gills showsever congestion of lamellar capillaries with marked aneurysm, necrosis and hemorrhage of lamellar epithelium and liver show sever hydropic degeneration and necrosis of hepatocytes, Ciprofloxacin was the most effective antibiotic against all isolated bacterial strains


2020 ◽  
Vol 36 (4) ◽  
pp. 126-135
Author(s):  
T.V. Shushkova ◽  
D.O. Epiktetov ◽  
S.V. Tarlachkov ◽  
I.T. Ermakova ◽  
A.A. Leontievskii

The degradation of persistent organophosphorus pollutants have been studied in 6 soil bacterial isolates and in 3 bacterial strains adapted for utilization of glyphosate herbicide (GP) under laboratory conditions. Significant differences in the uptake of organophosphonates were found in taxonomically close strains possessing similar enzymatic pathways of catabolism of these compounds, which indicates the existence of unknown mechanisms of activity regulation of these enzymes. The effect of adaptation for GP utilization as a sole phosphorus source on assimilation rates of several other phosphonates was observed in studied bacteria. The newly found efficient stains provided up to 56% of GP decomposition after application to the soil in the laboratory. The unresolved problems of microbial GP metabolism and the trends for further research on the creation of reliable biologicals capable of decomposing organophosphonates in the environment are discussed. organophosphonates, glyphosate, biodegradation, bioremediation, C-P lyase, phosphonatase, degrading bacteria Investigation of phosphonatase and genome sequencing were supported by Russian Science Foundation Grant no. 18-074-00021.


1988 ◽  
Vol 20 (1) ◽  
pp. 65-72 ◽  
Author(s):  
Rurik Skogman ◽  
Reino Lammi

The requirements imposed on the Finnish forest products industry by the water authorities have focused on the reduction of BOD and suspended solids in the wastewaters. The industry has tried to comply with these requirements, first through internal measures such as process changes and closed systems. When these have not been sufficient, external treatment has been resorted to. The Wilh. Schauman Company in Jakobstad has chosen activated sludge with extended aeration from among the available methods for treating effluent. The plant has operated since the beginning of 1986 with extremely good results. In addition to the reduction of BOD and suspended solids, there has been a marked decrease of chlorinated phenols. Chlorinated substances with higher molecular weight are also removed during the process.


1996 ◽  
Vol 34 (11) ◽  
pp. 87-92
Author(s):  
José Martinez ◽  
Xiaodi Hao

The SOLEPUR process for the treatment of pig slurry, based on the treatment effect of the soil, was developed in France to explore the notion that a simple biobarrier approach may be a potential efficient solution to the large accumulation of liquid animal wastes residues. The unit consists of (i) a managed field (3280 m2) which allows the total recovery of all the leachate water which percolates through growing ryegrass (Lolium perenne), to which the pig slurry is applied, (ii) a system of storage-pump-reactor for denitrification and (iii) a non-managed field for completing treatment. The process involves three operations: (1) overdosing the managed field with surplus slurry (about 1000 m3 pig slurry/ha.year applied from 1991 to 1994), (2) collecting and treating the nitrate-rich leachate and (3) irrigating the final treated water over other fields. This process decreased COD of pig slurry by 99.9 % and removed 99.9 % of phosphorus and approximately 80 % of nitrogen. The remaining nitrogen was oxidized in the soil into nitrate and leached out in the drainage water. The process of denitrification was selected to remove nitrate from the leachate and raw pig slurry was used as an external carbon source.


Author(s):  
Tamara Mainetti ◽  
Marilena Palmisano ◽  
Fabio Rezzonico ◽  
Blaž Stres ◽  
Susanne Kern ◽  
...  

AbstractConjugated estrogens, such as 17β-estradiol-3-sulfate (E2-3S), can be released into aquatic environments through wastewater treatment plants (WWTP). There, they are microbiologically degraded into free estrogens, which can have harmful effects on aquatic wildlife. Here, the degradation of E2-3S in environmental samples taken upstream, downstream and at the effluent of a WWTP was assessed. Sediment and biofilm samples were enriched for E2-3S-degrading microorganisms, yielding a broad diversity of bacterial isolates, including known and novel degraders of estrogens. Since E2-3S-degrading bacteria were also isolated in the sample upstream of the WWTP, the WWTP does not influence the ability of the microbial community to degrade E2-3S.


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