In Situ Production of Silver Bio Nanoparticles from Marine Biosurfactant Bacteria and Evaluation of Its Antibacterial Activity

ABSTRACT This study describes the genetic analysis of the riboflavin (vitamin B2) biosynthetic (rib) operon in the lactic acid bacterium Lactococcus lactis subsp. cremoris strain NZ9000. Functional analysis of the genes of the L. lactis rib operon was performed by using complementation studies, as well as by deletion analysis. In addition, gene-specific genetic engineering was used to examine which genes of the rib operon need to be overexpressed in order to effect riboflavin overproduction. Transcriptional regulation of the L. lactis riboflavin biosynthetic process was investigated by using Northern hybridization and primer extension, as well as the analysis of roseoflavin-induced riboflavin-overproducing L. lactis isolates. The latter analysis revealed the presence of both nucleotide replacements and deletions in the regulatory region of the rib operon. The results presented here are an important step toward the development of fermented foods containing increased levels of riboflavin, produced in situ, thus negating the need for vitamin fortification.

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Scaling-up of microbial electrosynthesis with multiple electrodes for in situ production of hydrogen peroxide

iScience ◽

10.1016/j.isci.2021.102094 ◽

2021 ◽

Vol 24 (2) ◽

pp. 102094

Author(s):

Rusen Zou ◽

Aliyeh Hasanzadeh ◽

Alireza Khataee ◽

Xiaoyong Yang ◽

Mingyi Xu ◽

...

Keyword(s):

Hydrogen Peroxide ◽

Scaling Up ◽

Microbial Electrosynthesis ◽

Multiple Electrodes ◽

Production Of Hydrogen ◽

In Situ Production

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A novel zinc complex with antibacterial and antioxidant activity

BMC Chemistry ◽

10.1186/s13065-021-00745-2 ◽

2021 ◽

Vol 15 (1) ◽

Author(s):

Yun Zhang ◽

Xiaojing Li ◽

Jia Li ◽

Md. Zaved Hossain Khan ◽

Fanyi Ma ◽

...

Keyword(s):

Antibacterial Activity ◽

Acute Toxicity ◽

Intestinal Absorption ◽

Antioxidant Activities ◽

Zinc Ion ◽

Water Soluble ◽

Zinc Supplement ◽

Citrate Complex ◽

Morphology Characterization

Abstract Background In order to enhance the antibacterial activity and reduce the toxicity of Zn2+, novel complexes of Zn(II) were synthesized. Results A water-soluble zinc-glucose-citrate complex (ZnGC) with antibacterial activity was synthesized at pH 6.5. The structure, morphology, characterization, acute toxicity, antibacterial and antioxidant activities, and in situ intestinal absorption were investigated. The results showed that zinc ion was linked with citrate by coordinate bond while the glucose was linked with it through intermolecular hydrogen bonding. The higher the molecular weight of sugar is, the more favorable it is to inhibit the formation of zinc citrate precipitation. Compared with ZnCl2, ZnGC complex presented better antibacterial activity against Staphylococcus aureus (S. aureus, Gram-positive) and Escherichia coli (E. coli, Gram-negative). Conclusions The results of acute toxicity showed no obvious toxicity in this test and in situ intestinal absorption study, suggesting that ZnGC complex could be used as a potential zinc supplement for zinc deficiency.

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Ship Drag Reduction by Microalgal Biopolymers: A Feasibility Analysis

Journal of Ship Research ◽

10.5957/jsr.2007.51.4.326 ◽

2007 ◽

Vol 51 (04) ◽

pp. 326-337

Author(s):

K. Gasljevic ◽

E. F. Matthys

Keyword(s):

Drag Reduction ◽

Consumption Rate ◽

Synthetic Polymers ◽

Point Of View ◽

Technical Issues ◽

Fuel Costs ◽

Propulsion Power ◽

Ship Speed ◽

In Situ Production

We have investigated the feasibility of using high-molecular-weight polysaccharides produced by marine microalgae to reduce the drag on ships and therefore to be able to reduce the needed propulsion power and fuel costs or, alternatively, to increase the ship speed. Experimental and analytical studies were used to answer four critical questions:How suitable are the biopolymers for drag reduction on ships?What is the needed polymer consumption rate at a given level of drag reduction?What is the achievable polymer production rate that can be achieved by the microalgae?What are possible modes of implementation of the proposed technology? It is seen that in situ production of biopolymers by microalgae growing on the hull may be a possible approach to polymeric ship drag reduction. Production of biopolysaccharide off the ship and even harvesting it from the ocean are other possibilities. The use of biopolymers is naturally advantageous from an environmental point of view as well. Some comparison of biopolymers and synthetic polymers is also presented. Several technical issues remain to be investigated, but the information available suggests that biopolymers may be the best additives for drag reduction on ships.

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Facile one pot microbe-mediated in situ synthesis and antibacterial activity of reduced graphene oxide-silver nanocomposite

Nanotechnology ◽

10.1088/1361-6528/ac4521 ◽

2021 ◽

Author(s):

Ashwini Patil

Keyword(s):

Antibacterial Activity ◽

Graphene Oxide ◽

Zeta Potential ◽

Reduced Graphene Oxide ◽

In Vitro Dissolution ◽

Size Analysis ◽

X Ray ◽

Reduced Graphene

Abstract The present research deals with the development of a novel bioinspired in situ fabrication of reduced graphene oxide (rGO)-silver nanoparticle (AgNPs) nanocomposite (rGO@AgNCs) using microbes namely Pseudomonas aeruginosa (PA) and Staphylococcus aureus (SA). The fabricated rGO@AgNCs were characterized using Ultraviolet-visible (UV) spectroscopy, Fourier-transform infrared spectroscopy (FTIR), particle size analysis, polydispersity index (PDI), zeta potential analysis, energy dispersive X-ray analysis (EDAX), Raman spectroscopy, powder X-ray diffraction (PXRD), high-resolution transmission electron microscopy (HR-TEM) analysis, etc. Furthermore, the rGO@AgNCs-PA and rGO@AgNCs-SA interaction with serum protein, pH stability study, and in vitro dissolution of AgNPs were also performed. The research findings of the proposed study demonstrated the simultaneous reduction of graphene oxide (GO) and AgNPs and the formation of rGO@AgNCs in the presence of microbes. The in vitro dissolution studies of rGO@AgNCs composites showed better AgNPs dissolution with controlled release and offered remarkable matrix integrity throughout the dissolution period. The size and stability of rGO@AgNCs-PA and rGO@AgNCs-SA had no significant changes at physiological pH 7.4. A minimal decrease in the zeta potential of rGO@AgNCs was observed, which may be due to the weak interaction of nanocomposites and albumin. The antibacterial application of the synthesized nanocomposite was evaluated against a pathogenic mastitis-forming bacterium. The obtained results suggested an admirable antibacterial activity of synthesized nanocomposites against the tested microbes. This knowledge will assist the scientific fraternity in designing novel antibacterial agents with enhanced antibacterial activity against various veterinary pathogens in near future.

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In situ synthesis of ZnO Nanoparticles on plasma treated cotton fabric utilizing durable antibacterial activity

Journal of Natural Fibers ◽

10.1080/15440478.2017.1349714 ◽

2017 ◽

Vol 15 (5) ◽

pp. 639-647 ◽

Cited By ~ 5

Author(s):

Sheila Shahidi ◽

Hootan Rezaee ◽

Abosaeed Rashidi ◽

Mahmood Ghoranneviss

Keyword(s):

Antibacterial Activity ◽

Cotton Fabric ◽

Zno Nanoparticles ◽

In Situ Synthesis

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A green in situ synthesis of silver nanoparticles on cotton fabrics using Aloe vera leaf extraction for durable ultraviolet protection and antibacterial activity

Textile Research Journal ◽

10.1177/0040517516671124 ◽

2016 ◽

Vol 87 (19) ◽

pp. 2407-2419 ◽

Cited By ~ 17

Author(s):

Qingqing Zhou ◽

Jingchun Lv ◽

Yu Ren ◽

Jiayi Chen ◽

Dawei Gao ◽

...

Keyword(s):

Silver Nanoparticles ◽

Antibacterial Activity ◽

Aloe Vera ◽

Cotton Fabrics ◽

In Situ Synthesis ◽

Uv Protection ◽

X Ray ◽

Jcpds File ◽

Laundering Durability

This study presented a simple and environmentally friendly method of in situ synthesis of silver nanoparticles (AgNPs) on cotton fabrics for durable ultraviolet (UV) protection and antibacterial activity using Aloe vera leaf extraction (AVE) as a reducing and stabilizing agent. Cotton fabrics were pretreated in water, and then immersed in AgNO3 and AVE, respectively. Cotton fabrics were characterized by small angle X-ray diffraction (XRD), scanning electron microscopy (SEM), thermogravimetric analysis, UV protection, antibacterial activity, and laundering durability. Comparing with the smooth surface of the control cotton fabric, SEM and energy dispersive X-ray spectrometry (EDX) results showed that there were a considerable number of Ag2O and AgNPs loading on the surface of the pretreated and Ag loaded cotton fabrics. The XRD pattern indicated, respectively, the existence of Ag2O and AgNPs, the structures of which were similar to JCPDS File No.65-3289 and JCPDS File No. 01-071-4613 on the pretreated and Ag loaded cotton fabrics. The pretreated and Ag loaded cotton fabrics showed excellent UV protection, antibacterial activity, and laundering durability, especially the Ag loaded cotton fabric, of which the UV protection factor value and transmission of UVA were 148 and 1.11%, respectively, after 20 washing cycles, and the clear zone width was more than 4 mm against E. coli or S. aureus. AgNPs facilitated the improvement of the thermal property of the cotton fabrics. Thus this facile in situ reduction of AgNPs with AVE may bring a promising and green strategy to produce functional textiles.

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