Arsenic is a toxic metalloid which is widely distributed in nature. It is normally present as arsenate under oxic conditions while arsenite is predominant under reducing condition. The major discharges of arsenic in the environment are mainly due to natural sources such as aquifers and anthropogenic sources. It is known that arsenite salts are more toxic than arsenate as it binds with vicinal thiols in pyruvate dehydrogenase while arsenate inhibits the oxidative phosphorylation process. The common mechanisms for arsenic detoxification are uptaken by phosphate transporters, aquaglyceroporins, and active extrusion system and reduced by arsenate reductases via dissimilatory reduction mechanism. Some species of autotrophic and heterotrophic microorganisms use arsenic oxyanions for their regeneration of energy. Certain species of microorganisms are able to use arsenate as their nutrient in respiratory process. Detoxification operons are a common form of arsenic resistance in microorganisms. Hence, the use of bioremediation could be an effective and economic way to reduce this pollutant from the environment.

There has been an explosion of probiotic incorporated based product. However, many reports indicated that most of the probiotics have failed to survive in high quantity, which has limited their effectiveness in most functional foods. Thus, to overcome this problem, microencapsulation is considered to be a promising process. In this study, Lactococcus lactis Gh1 was encapsulated via spray-drying with gum Arabic together with Synsepalum dulcificum or commonly known as miracle fruit. It was observed that after spray-drying, high viability (~10⁹ CFU/mL) powders containing L. lactis in combination with S. dulcificum were developed, which was then formulated into yogurt. The tolerance of encapsulated bacterial cells in simulated gastric juice at pH 1.5 was tested in an in-vitro model and the result showed that after 2 h, cell viability remained high at 1.11 × 10⁶ CFU/mL. Incubation of encapsulated cells in the presence of 0.6% (w/v) bile salts showed it was able to survive (~10⁴ CFU/mL) after 2 h. Microencapsulated L. lactis retained a higher viability, at ~10⁷ CFU/mL, when incorporated into yogurt compared to non-microencapsulated cells ~10⁵ CFU/mL. The fortification of microencapsulated and non-microencapsulated L. lactis in yogurts influenced the viable cell counts of yogurt starter cultures, Lactobacillus delbrueckii subs. bulgaricus and Streptococcus thermophilus.

A novel peptide nuclide acid (PNA) electrochemical biosensor based on reduced graphene oxide (NH₂-rGO)/2,2,6,6-tetramethylpiperidin-1-yl)oxyl nanocrystalline cellulose (TEMPO-NCC) for the detection ofMycobacterium tuberculosis(M. Tuberculosis) is described. In this study, the nanohybrid films NH₂-rGO/TEMPO-NCC were immobilized onto screen-printed carbon electrode (SPE) via a simple drop-coating method. The electrochemical characterization of the designed electrode was investigated using cyclic voltammetry (CV) and impedance spectroscopy (EIS). Meanwhile, the sensitivity and selectivity of the designed biosensor againstM. tuberculosiswere measured by the differential pulse voltammetry (DPV). The response of the PNA probe-modified (NH2-rGO)/TEMPO-NCC demonstrated that the fabricated biosensor was able to distinguish between complementary, noncomplementary, and one-base mismatch DNA sequences using methylene blue (MB) as the electrochemical indicator. The developed electrochemical biosensor exhibited a linear calibration curve in the concentration range of1×10−8Mto1×10−13Mwith the limit of detection of3.14×10−14M. The developed electrochemical biosensor has also been tested with a polymerase chain reaction (PCR) product ofM. tuberculosisDNA which has shown successful results in distinguishing between negative and positive samples of M. tuberculosis.