Catalyst: Strategic – New Zealand-China joint research partnerships 2022

AgResearch (Food System Integrity Team, NZ) and Jiangnan University (the China Key State Laboratory of Food Science and Technology & the International Joint Research Laboratory for Food Safety, China) have agreed to build on mutual interests to control persistent and hard-to-kill microorganisms in market-sensitive foods such as infant formula. C. sakazakii, is a food borne pathogen that can cause meningitis and septicaemia in infants and is a huge concern to dairy industries. These bacteria can form biofilms and are resistant to various stress conditions assisting survival in environment for a very long time.

This collaboration aims to develop a novel dual light system applicable for real-world application. Both partners are focusing their R&D on alternative clean light-based technologies to reduce the risk of foodborne pathogens. AgResearch has been actively investigating the combination of 222nm (far-UVC) and 405nm blue light (BL) as a promising non-thermal, chemical free disinfection that is safer to use in presence of workers compared with UVC. Previous research by the AgResearch team has shown that in combination, far-UVC and BL has a synergistic effect on the inactivation of Coronavirus and E. coli. However, the mechanism for this enhanced ability has not yet been determined, Jiangnan University will add considerable contributions with their relevant experience and skills on photoinactivation research and their complementary expertise will be essential during the technology advancement.

A major technical benefit of BL LED is it is significantly more energy efficient than UVC LED, generating much less heat, and the resulting products will be smaller and with less passive and or active cooling required. However, one major limitation of using UVC LED in antimicrobial technology is the short penetration depth of UV light, which impairs effectiveness in inactivating microbes that reside deeper than the surface of solid or liquid media. By combining far-UVC with BL we can take advantage of BL’s enhanced ability to penetrate through plastics, glass and into water and fabrics.

R&D undertaken will accelerate the implementation of the technology. Combined results will inform the design of dual light systems appropriate for automated dairy processing lines. The generation of ready-to-use technology is expected to attract industrial investment and ultimately to achieve an upgrade of food safety infrastructure for infant formula production in both nations and benefit global end-customers.

In the Southern Ocean, climate change is affecting regional and seasonal patterns in ocean conditions such as temperature, currents, wind-mixing, and sea ice. This project aims to understand how climate change and fishing will affect species that are most directly relevant to both New Zealand’s and China’s strategic interests in the Ross Sea, namely Antarctic toothfish and species that are prey of toothfish and/or by-catch in the toothfish fishery. We propose 4 steps.

First, the likely effects of climate change and fishing on toothfish reproduction (recruitment) will be examined by embedding 'virtual' toothfish eggs and larvae in a high-resolution computer simulation. This model will have high spatial resolution to include complexities such as eddies and the dynamics of wind- and current-driven sea ice, and how they vary spatially and seasonally. Biological data will be used in conjunction with the model to test hypotheses about larval survival. This work builds on a foundation established in Ross-RAMP but will be developed further using a suite of Earth-system models (CMIP6) to provide future scenarios of oceanographic and bio-physical change under different radiative forcing.

Second, we will use samples collected by research and fishing ships throughout the area to better understand the spatial and seasonal patterns where toothfish and associated fish species have evolved to survive in the area. This will include using chemical analyses of fish tissues to identify how they move and are carried by currents throughout their lives. Piecing together the spatial structure of prey species is crucial to forecasting how these species could change in the future.

Third, we will refine information on trophic connections between key species in the Ross Sea region using new and proven biomarker tracing techniques, such as fatty acids and stable isotope analyses, together with stomach/gut analysis at scale.

Finally, the information will be brought together using spatially resolved multispecies models to understand how environmental conditions and fishing are likely to affect trophic (predator-prey) connections between toothfish and its main prey species in the future. Scenario analysis will be used to explore the effectiveness of management systems and to optimise future data collection and analysis. Our research will therefore assist managers in developing options to manage impacts on the population structure and connectivity, dynamics, and productivity of Antarctic toothfish, critical for meeting management objectives for the region for the benefit of New Zealand, China and all members of CCAMLR.