Development of a quantitative ELISA for SARS-CoV-2 vaccine candidate, NDV-HXP-S, with CpG 1018® adjuvant.

NDV-HXP-S is a Newcastle disease virus (NDV) vectored vaccine candidate which expresses the S-antigen of severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2). This vaccine candidate is under evaluation in human clinical studies with and without cytosine phosphate guanine (CpG) 1018® adjuvant. Existing potency methods for NDV-HXP-S do not allow for quantification of the S-antigen when the adjuvant is present. To support evaluation of NDV-HXP-S with CpG 1018® adjuvant, an inhibition enzyme-linked immunosorbent assay (ELISA) was developed to allow for quantification and stability assessments of the vaccine. A pilot 6-month stability study was conducted on NDV-HXP-S vaccine with and without CpG 1018® adjuvant under refrigerated conditions (2°C to 8°C) and accelerated stability testing conditions (40°C). The vaccine was mixed with and without CpG 1018® adjuvant in saline and maintained S-antigen content at 2°C to 8°C for the entire 6-month period. Additionally, a pilot controlled temperature chain (CTC) stability study was conducted at the completion of the 6-month study and demonstrated the possibility for this vaccine candidate to attain CTC stability labeling.

Nutrient drip irrigation for refractory hydrocarbon removal and microbial community shift in a historically petroleum-contaminated soil.

An adequate amount of nutrients is required to enable biodegradation of refractory hydrocarbons in petroleum-contaminated soil. In this study, a microcosm experiment was conducted using a drip fertigation method for petroleum-contaminated soil remediation. Nitrogen and phosphorus were homogeneously and periodically sprayed into a historically contaminated soil using a modified horticultural drip irrigation device. Various petroleum hydrocarbon fraction contents were then determined by gravimetry and gas chromatography (GC), and changes in the soil microbial community were analyzed by high throughput sequencing. After 90 days of remediation, the removal efficiencies of total petroleum hydrocarbon (TPH), saturates, aromatics, C7-C30 n-alkanes, and 16 PAHs were respectively enhanced by 21.5%, 25.5%, 12.4%, 10.4%, and 19.6% compared with the use of a single nutrient amendment application. The high throughput sequencing result showed that obvious changes had occurred in the soil microbial community compositions during drip fertigation; however, fungi were more sensitive to drip fertigation than bacteria. The resulting predominant bacterial and fungal genera were Dietzia, Nocardioides, Mycobacterium, Sphaerobacter, Leifsonia, and Aspergillus, Scolecobasidium, and Fusarium, respectively. Remediating polluted soils by regular fertigation ensures the automatic addition of even amounts of nutrients, which achieves high refractory hydrocarbon removal efficiencies. It is expected that this method can be applied in the in-situ remediation of petroleum-contaminated soil on a large scale.

[Microbial Community Structure Shift During Bioremediation of Petroleum Contaminated Soil Using High Throughput Sequencing].

The shift in microbial community structure during the bioremediation of oil-polluted soil was analyzed by high-throughput sequencing. The results demonstrated obvious changes in the soil microbial community structure and diversity during bioremediation. The species richness and evenness of the microbial community decreased substantially due to the bioaugmentation treatment. Proteobacteria became the predominant phylum, with a relative increase in abundance from 37.44% to 87.44%. Pseudomonas was the most dominant genus, which increased in abundance from 2.99% to 76.37%. In the biostimulation treated soil, the relative abundance of Proteobacteria decreased from 37.44% to 10.90%, while the phylum Firmicutes increased from 9.16% to 35.32%. At the genus level, the relative abundances of Exiguobacterium and Promicromonospora decreased from 8.49% and 18.96% to 2.19% and 14.97%, respectively. Nocardioides and Bacillus became the dominant genera and increased from 5.56% and 0.29% to 28.95% and 22.70%, respectively. The results indicated that bioaugmentation substantially influenced the soil microbial diversity and community structure. Additionally, the biostimulation treatment maintained the balance in the soil microbial community structure. The stabilization of bacteria community structure is beneficial to petroleum biodegradation in the soil.