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A Review on L-Asparaginase
Published in Se-Kwon Kim, Marine Biochemistry, 2023
The irreversible conversion of blood glutamine into glutamic acid and ammonia is because of the presence of glutaminase activity of asparaginase. The resulting glutamate reacts with sodium in blood and gives rise to the production of monosodium glutamate (Kurtzberg et al., 2003). There are reports suggesting that due to the presence of glutaminase activity of asparaginase, leukemia patients suffer from many life-threatening side effects, such as leucopenia, acute pancreatitis, immunosuppression, hyperglycemia, thromboembolysis and neurological seizures (Devi et al.,2012; Ramya et al.,2012). Therefore, it is necessary to make a search for glutaminase-free asparaginase from the native microorganisms. In the control of leukemia, the pharmacodynamics of asparaginase differs by formulation (Pinheiro and Boos, 2004). The treatment mainly depends on the intensity of the dose and duration of the treatment of asparaginase rather than the type of asparaginase used (Silverman et al., 2001; Pui and Evans, 2006). Currently, L-asparaginase obtained from Erwinia carotovora and Escherichia coli is of commercial importance. Other microbes, such as Bacillus sp., Corneybacterium glutamicum, Enterobacter sp., Pseudomonas stutzeri and others, also produce a feasible amount of enzyme. As far as fungi are concerned, Aspergillus oryzae was found to synthesis large amount of enzyme.
Green Synthesis of Nanoparticles in Oligonucleotide Drug Delivery System
Published in Yashwant Pathak, Gene Delivery, 2022
Manish P. Patel, Praful D. Bharadia, Kunjan B. Bodiwala, Mustakim M. Mansuri, Jayvadan Patel
Synthesis of nanoparticles using a bacterial strain emerged due to the technique’s green prospect. These bacteria can mobilize or immobilize metal ions, along with reducing ion concentration and accumulation of these ions in their cell wall. Pseudomonas stutzeri AG259 is the first bacterial strain to show silver nanoparticles formation; this strain is isolated from silver mines. After that discovery, significant research has been done in this area, and many bacterial strains are isolated for synthesis of nanoparticles (Prabhu and Poulose, 2012). This approach has immense potential and a bottom up type of synthesis. Magnetotactic bacteria and S layer lattices in prokariyotic cells like bacteria are capable of synthesis of metal ions (xie et al., 2009; Györvary et al., 2004). Pseudomonas stutzeri and Pseudomonas aeruginosa can get through at even higher concentrations of metal ions (Husseiny et al., 2007). Thiobacillus ferrooxidans, T. thiooxidans, and Sulfolobus acidocaldarius convert Fe3+ into Fe2+ (Korbekandi et al., 2009). Bacillus cereus, B. subtilis, E. coli, and P. aeruginosa can decrease concentrations of silver ions, cadmium ions, cupric ions, and lanthanum ions (Du and Li, 2016). Bacterial strains or species used in synthesis of nanoparticles are shown in Table 4.2.
Prospects of Local Flora of Trans-Himalayan Region of Ladakh for Various Medicinal Uses
Published in Parimelazhagan Thangaraj, Medicinal Plants, 2018
Gyan P. Mishra, Tsering Stobdan, Parimelazhagan Thangaraj, Tania Seth, Bijendra Singh
In Ayurveda, the root-bark is given in splenic, renal and hepatic conditions and also as an analgesic, anthelmintic, deobstuent, diuretic, expectorant and vasoconstrictive (Chiej 1984). Internally it is used in the treatment of gastrointestinal infection, diarrhoea and rheumatism (Bown 1995). Externally, it is used to treat skin conditions, capillary weakness and easy bruising (Genders 1994; Bown 1995). Alkaloids, to the tune of 0.91% from root-bark and 0.86% from seeds, are isolated, and the maximum alkaloid content was found in the roots, of which stachydrine constituted 87.43% of the total alkaloid present (Sadykov et al. 1981). In Unani medicine, the decoction of root bark is prescribed as a deobstruent to the liver and spleen, as an anthelmintic and anti-inflammatory agent (Chopra et al. 1999). Four bacterial strains (viz. Pseudomonas stutzeri var. mendocina, Comamonas sp., Agrobacterium tumefaciens bivar. 2 and Sphignobacterium sp.), isolated from the rhizosphere of capers, were found to be able to fix N2 (Andrade et al. 1997). The ethanolic extract of C. spinosa root bark reported anthelmintic activity. It acts as anti-allergic and antihistaminic agent (Zhan 1978).
Identification of Bacterial and Fungal Pathogens by rDNA Gene Barcoding in Vitreous Fluids of Endophthalmitis Patients
Published in Seminars in Ophthalmology, 2020
Appavu Selva Pandiyan, Rajapandian Siva Ganesa Karthikeyan, Gunasekaran Rameshkumar, Sagnik Sen, Prajna Lalitha
On direct culturing of vitreous samples, bacterial growth was observed in 14/88 samples (15.9%) and fungal growth in 3/88 samples (3.4%) (Table 2). Of the bacterial culture-positive isolates, 10 were gram-positive (58.8%) and four gram-negative (23.5%). Among the gram-positive bacteria, Staphylococcus spp., were found to be the most predominant (6/88, 6.8%), followed by Streptococcus spp. (2/88, 2.3%), Enterococcus gallinarum (1/88) and Diphtheroids (1/88). In the gram-negative group, Pseudomonas stutzeri was identified in 2 patients (2/88, 2.3%) followed by Rhizobium sp (1/88) and Neisseria cinerea (1/88). Three fungal isolates were identified as Aspergillus fumigatus, Candida albicans, and Exerohilum rostratum.
Current advances in the algae-made biopharmaceuticals field
Published in Expert Opinion on Biological Therapy, 2020
Sergio Rosales-Mendoza, Karla I. Solís-Andrade, Verónica A. Márquez-Escobar, Omar González-Ortega, Bernardo Bañuelos-Hernandez
Algae cultivation at large scale could be greatly facilitated by reducing contamination in bioreactors and thus approaches to avoid the growth of other organisms are desirable to overcome microbial contamination. Loera-Quezada et al. [64] and Sandoval-Vargas et al. [65] have developed a strategy based on a selective environment that favors monocultures of selected algal lineages grown in open systems. The approaches are based on the fact that the majority of living organisms can only use phosphate (Pi) as source of phosphorus, but not other reduced chemical forms of P such as phosphite (Phi) or hypophosphite (HPhi) [66]. Thus by introducing new genes the selected algae acquire the capacity of using Phi as P source, having a competitive advantage over competitors when grown on a medium containing Phi as the sole source of P. Loera-Quezada et al. [64] demonstrated that C. reinhardtii assimilated Phi by expressing the ptxD gene from Pseudomonas stutzeri WM88, which encodes a phosphite oxidoreductase able to oxidize Phi into Pi. The authors proved that the nuclearly-engineered C. reinhardtii lines have the capacity to use Phi as P source and dominate the culture system in the presence of naturally occurring contaminants or even when deliberately inoculated with another algal species. In a similar approach but targeting chloroplast expression, Sandoval-Vargas et al. [65] reported that Phi assimilation can also be achieved by expressing a codon-optimized ptxD gene in C. reinhardtii. These are possible approaches for the production of biopharmaceuticals at the large scale, decreasing the contamination risk in the bioreactor.
Continuous flow system for biofilm formation using controlled concentrations of Pseudomonas putida from chicken carcass and coupled to electrochemical impedance detection
Published in Biofouling, 2020
Daoyuan Yang, José I. Reyes-De-Corcuera
Based on the Randles circuit model, the Rct decreased by 61, 56 or 30 kΩ from 207 ± 12, 222 ± 12 or 206 ± 2 kΩ at time 0 to 146 ± 2 at 63 h, 166 ± 7 at 49 h or 176 ± 3 kΩ at 12 h corresponding to 10,000-fold, 1,000-fold or 100-fold dilution, respectively. Based on the biofilm model, the Rb decreased from 208 ± 12, 223 ± 12 or 207 ± 2 kΩ at time 0 to 146 ± 2 at 63 h, 166 ± 7 at 49 h or 176 ± 3 kΩ at 12 h corresponding to 10,000-fold, 1,000-fold or 100-fold dilution, respectively. The decrease in Rct as the biofilm grew is in agreement with many other reports (Bayoudh et al. 2008; Xu et al. 2010; Malvankar, Tuominen et al. 2012; Babauta and Beyenal 2017). The decrease in Rct might come from the charge transfer increase resulting from the attachment of charged bacterial cells (Dheilly et al. 2008). The decrease in Rct might also be related to the increase in the biofilm conductivity. Malvankar, Tuominen et al. (2012) suggested that the Rct, which arose from the activation barrier at the interface of biofilm and electrode, was lowered when the electrons carried more energy after passing through a more conductive biofilm. The biofilm may become more conductive as it grows and results in the decrease in Rct (Babauta and Beyenal 2017). However, physical and physiological interpretation of equivalent circuits are not straightforward. Furthermore, the electrochemical properties of a biofilm depend on the microbes that form the biofilm. The conductivity of biofilm varies with the microbial strain. Geobacter sulfurreducens, Pseudomonas stutzeri and Staphylococcus epidermidis formed conductive biofilms (Bayoudh et al. 2008; Babauta and Beyenal 2017). But biofilms of Pseudomonas aeruginosa, Bacillus subtilis, and Escherichia coli had low conductivity (Dheilly et al. 2008; Malvankar, Lau et al. 2012). If the biofilm is poorly conducting, the cells attached to the surface become an insulating barrier inhibiting the charge transfer and a higher Rct can be detected by EIS. In addition, the ionic strength of the electrolyte also needs to be taken into consideration. The EIS response to the formation and the dynamics of mixed-culture biofilms has not yet been characterized.