Today, many different methods are applied for the correct use of foods and to prevent their deterioration. Ensuring healthy conditions for people in food consumption and consumption of healthy foods is very important for human welfare. In this study, food spoilage, the factors that cause food spoilage, its effects on a global basis, food transport systems (cold chain) and measures that prevent or delay food spoilage are discussed.

Background. The bystander effects, whereby naive (bystander) Microbial cells near Microbial cells directly exposed to certain treatment show responses that would not have happened in the absence of the directly targeted Microbial cells. In this article, we evaluated the effects of photoactivated disinfection (PAD)-induced bystander on Microbial cell survival and metabolic activity of Porphyromonas gingivalis. Methods. Bystander effects induced by whole bacterial cell suspension (WBCST), cell-free supernatants fluid (CFSFT), and bacterial cell pellet (BCPT) obtained from P. gingivalis culture treated with Curcumin (Cur)-PAD on cell survival of P. gingivalis were determined using Microbial viability assay. Results. P. gingivalis cell survival reduced by 71. 5% (P =0. 001) and 64. 6% (P =0. 01) after exposure to WBCST and CFSFT, respectively. The P. gingivalis population increased by 3. 7% (P =0. 7) after exposure to BCPT. Conclusions. The results of the current study revealed that Cur-PAD could significantly reduce Microbial cell survival through the bystander effects and can enhance the efficiency of PAD as an adjunct therapeutic strategy for treatment of local infections.

Background: Bacillus subtilis can produce urease in the presence of urea as the main carbon source and induce mineralization in the presence of precipitable cations.Objectives: The objective of our study was to demonstrate that Bacillus subtilis catabolizes glucose first in the presence of both glucose and urea carbon sources. Using its feature of catabolizing glucose first to delay the mineralization time, it proved its potential application in enhancing the recovery of heterogeneous reservoirs.Material and Methods: The metabolic process of Bacillus subtilis was monitored by changing the glucose content in the bacterial medium by UV spectrophotometer and pH meter. Using a non-homogeneous physical model, experiments were conducted to improve reservoir recovery by Microbial mineralization after polymer oil drive.Results: The higher the glucose content in the medium, the longer the time for the pH of the bacterial solution to reach 7 and the longer the end of the logarithmic phase of growth. the glucose content of the 48 h medium was significantly correlated with the consumption of the bacteria and the quality of the precipitation. In the oil drive experiment: the permeability of the high permeability model was reduced from 1200 md to 136 md with a reduction rate of 88.6 %, and the permeability of the low permeability model was reduced by 22 md, and the crude oil recovery was increased by 7.9 %.Conclusions: It was demonstrated that the addition of glucose to the culture medium retarded the mineralization of bacteria. Only 0.2 times the pore volume of the bacterial solution and the cementing solution is required to form an effective seal, thus improving the recovery of crude oil.

Soil water repellency (SWR) is a widespread natural phenomenon that results from a complex interplay between the hydrosphere, lithosphere, biosphere, atmosphere, and anthroposphere. Sewage sludge application can induce soil water repellency (SWR), impacting soil hydraulic properties. This research examined the effect of soil Microbial manipulation (removal and addition) on SWR and water retention in a silty-clay-loam soil amended with varying sludge amounts. Three levels of water repellency (zero, weak and strong) were artificially created in a silty clay loam soil by adding urban sewage sludge. The results showed that the elimination of soil microorganisms such as fungi and bacteria and their interactions significantly (P≤0.01) affect the hydrophobicity, soil water retention curve (both wetting and drying) of the sludge-treated soils. Microbial exclusion significantly reduced SWR (21-49%), suggesting that Microbial activity contributes to the formation of hydrophobic compounds. Conversely, Microbial inoculation increased SWR (27.5-50%), indicating Microbial production or transformation of hydrophobic substances.  It is concluded that soil microorganisms can increase soil water repellency. Also, soil microorganisms can affect the soil water retention curve through their influence on soil water holding capacity, depending on Microbial diversity. These findings highlight the critical influence of Microbial activity on SWR and water holding capacity in sludge-treated soils.

Biocementation through Microbial induced carbonate precipitation (MICP) is a recently developed new branch in geotechnical engineering that improves the mechanical properties of bio-treated soils. The potential application of MICP to handle problems such as liquefaction and erosion has been established; this technique offers an environmentally friendly, cost-effective and convenient alternative to traditional soil improvement approaches. Nevertheless, in spite of the widespread demonstration of the process at laboratory scale, few field and practical applications have been implemented to assess the efficiency of the biochemical process. Therefore, this paper presents a review of the utilization of MICP for soil improvement and discusses the treatment process including the key constituents involved and the main affecting factors, especially in field scale applications. The major contribution of this research is to identify the main parameters restricting the application of this method on site. Finally, technical and commercial progress in the industrial adoption of the technology and the main challenges that are ahead for the future research prior to real practical application are briefly discussed.

Microbial-induced calcite precipitation (MICP) is a relatively green and sustainable soil improvement technique. It refers to a chemical reaction network that is managed and controlled within soil through biological activity and whose byproducts alter the engineering properties of soil. To treat soil, first, the Microbial population in-situ is augmented by the injection of additional urease positive bacteria and then reagents are added. This paper provides an overview of the factors affecting the MICP in soil. Several factors including nutrients, bacteria type, geometric compatibility of bacteria, bacteria cell concentration, fixation and distribution of bacteria in soil, temperature, reagents concentration, pH, and injection method are introduced. These factors were found to be essential for promoting successful MICP soil treatment. Furthermore, a preliminary laboratory test was carried out to investigate the potential application of the technique in improving the strength and impermeability of a sand specimen and utilized techniques, materials, methods and empirical process during the test are explained. The results showed that as a result of the calcite precipitation, shear wave velocity increased up to 1000m/s and UCS strength increased to about 300Kpa and permeability of soil decreased significantly upon MICP treatment.