China
Africa
Explore chapters and articles related to this topic
Harnessing Indigenous Bioresources for Development of Diagnostics for Detection and Confirmation of Infectious Agents in Nigeria
Published in Hajiya Mairo Inuwa, Ifeoma Maureen Ezeonu, Charles Oluwaseun Adetunji, Emmanuel Olufemi Ekundayo, Abubakar Gidado, Abdulrazak B. Ibrahim, Benjamin Ewa Ubi, Medical Biotechnology, Biopharmaceutics, Forensic Science and Bioinformatics, 2022
E. O. Ekundayo, J. C. Igwe, Ifeoma M. Ezeonu
Microorganisms require nutrients and other substances which include carbon, nitrogen, inorganic phosphate and sulphur, trace elements, vitamins and water for growth. A typical microbiological culture medium (as shown in Table 5.2) must contain available sources of these nutrients and substances. Traditionally, these growth requirements were supplied through sources such as meat infusion, beef or yeast extracts. However, it was discovered that addition of peptones improved the performance of culture media. Peptones are digests of proteins which provide readily available nitrogen, carbon and essential amino acids that enhance rapid growth of microorganisms. Different types of peptones have been produced to meet the different requirements of different organisms. Some fastidious bacteria may also require additional growth factors to grow in artificial medium. Culture media formulations are based on the ability of bacteria to utilize the components of the media. For diagnostic purposes, media also contains substances like reagents, dyes or antibiotics that make them selective for certain groups of bacteria. Others contain indicators that make them differential.
Characterization of Microorganisms by Pyrolysis-GC, Pyrolysis-GC/MS, and Pyrolysis-MS
Published in Karen D. Sam, Thomas P. Wampler, Analytical Pyrolysis Handbook, 2021
Stephen L. Morgan, Bruce E. Watt, Randolph C. Galipo
Bergey’s Manual of Determinative Bacteriology [1] catalogs over 250 bacterial genera. Traditional microbiological identification of bacterial species is based on appearance under a microscope (shape, size, presence of particular structures), response to staining (e.g., the classic Gram stain), or indirect characteristics (growth under aerobic or anaerobic conditions, generation of specific enzymes or biochemical products, etc.). Morphology is closely related to taxonomy but its use for microbial characterization is not definitive [2,3]. Structural characteristics of “Gram type” (e.g., thick peptidoglycan in Gram-positive organisms versus lipopolysaccharide in Gram-negative organisms) do not always correlate with the results of the Gram stain. Other cell types (such as acid-fast species) also exist [4,5]. The presence of specific enzymes, the response of an organism to growth substrates, or susceptibility of an organism to specific antibiotics is often due to metabolism rather than structure. Although valuable for identification, the use of these largely phenotypic characteristics requires culturing and isolation of viable cells, which can be time-consuming and may even fail for fastidious organisms [6].
Characterizing Microbial Quality of Water Supply
Published in Edwin E. Geldreich, Microbial Quality of Water Supply in Distribution Systems, 2020
Commercial speciation kits are acceptable with few confusable identities; however, not all aquatic organisms will provide sufficient growth to generate a metabolic response. In some instances, organisms isolated may be too fastidious in their growth requirements and not respond to the incorporated nutrient base medium. Such was the case in a study of heterotrophic bacterial populations encountered in water distribution systems.64 In this investigation, bacteria initially recovered on standard plate count agar from drinking water would not subculture unless a low-nutrient medium (R3-A) was used. Furthermore, growth and reaction on API-20E was often difficult or negative for these strains. While this problem has the greatest impact on noncoliform strains in the heterotrophic bacterial population, some species identification difficulties could be a possibility with stressed coliforms and those strains that have receded into the ultramicrobacteria phase of survival in the distribution pipe network.
High cell density continuous fermentation for L-lactic acid production from cane molasses
Published in Preparative Biochemistry & Biotechnology, 2023
Vaishali Gupta, Annamma A. Odaneth, Arvind. M. Lali
Considering the potential of molasses sugars for the LA producing microbes, it was subsequently investigated in both pretreated (hydrolyzed) and untreated (unhydrolyzed) forms which may have same or better effects on the Lactobacillus cells. The sugarcane molasses utilized in the LA fermentation process was primarily composed of sucrose (Table 2). Due to the fact that only a few Lactobacillus species are known to metabolize sucrose, the disaccharide was hydrolyzed in the current study to test the compatibility of the Lb. delbrueckii. After the acid-base pretreatment process, the total molasses glucose and fructose concentrations were held at 15 g/L for the shake-flask trial. The initial pH of the molasses solution was kept around 6.5 since it significantly encourages the optimal growth of Lb. delbrueckii, hence increasing the associated LA yield.[34] As a result, dilute HNO3 and dilute NH4OH were utilized for acid-base hydrolysis because they give the fastidious Lactobacillus bacteria the required nitrogen and ammonium ions at the same time.
Culturing the uncultured microbial majority in activated sludge: A critical review
Published in Critical Reviews in Environmental Science and Technology, 2023
Based on the experience accumulated from the traditional cultivation, a high-throughput cultivation technology that combined with rapid identification by matrix-assisted laser desorption ionization time-of-flight (MALDI-TOF) mass spectrometry (MS) was created, i.e. “culturomics” (Lagier et al., 2012, 2018). In general, culturomics firstly divides the sample into several parts to conduct high-throughput enrichment and cultivation with different culture conditions, then applies MALDI-TOF MS to identify the isolates, and finally adopts 16S rRNA and genome sequencing to validate and report the new taxa. Culturomics has made advanced progress since proposed especially after the rapid development and wide application of MALDI-TOF MS because culturomics cannot stand alone without the fast identification methods. In 2015, a culturomics study summarized 18 powerful media that could cultivate half of the isolated bacteria in human gut and pointed out the key components of rumen fluid and sheep blood (Lagier et al., 2015b). And another research introduced different culture strategies of clinical microbiology via culturomics, especially the specific approaches for those fastidious bacteria such as Mycoplasma and Spirochetes (Lagier et al., 2015a). In addition to the examples mentioned above, culturomics also plays a key role in microorganisms resolution of other ecosystems likewise the archaea in hypersaline environments (Durán-Viseras et al., 2021) and bacteria in plants (Sarhan et al., 2019). Currently, the major disadvantage of culturomics remains the high workload and inability to test large samples simultaneously as other methods, for example, metagenomics.
Effective sequestration of chromium by bacterial biosorption: a review
Published in Preparative Biochemistry & Biotechnology, 2021
Rinaldo John, Anand Prem Rajan
Bacteria in comparison to other microbes are mostly non-fastidious and show higher specific growth rates.[64–66] A notable point is that recovering heavy metals via strictly anaerobic microbes that are active is very difficult, as proper care has to be given in maintaining their survival conditions during the bioabsorption process, whereas bioabsorbents that are from inactive microbes have no such needs.[67,68]