Enhanced shelf-life of the formulated biocontrol agent Bacillus amyloliquefaciens CPA-8 combining diverse packaging strategies and storage conditions

Abstract

Two effective biocontrol products (named as BA3 and BA4) based on Bacillus amyloliquefaciens CPA-8 have been reported as a potential alternative to chemical applications against brown rot caused by Monilinia spp. on stone fruit. To have practical use, this study aimed to describe the best packaging strategies (bags or flasks, atmosphere, and temperature of storage) to not only guarantee efficacy but also stability and ease of application of the products to be handled through the normal channels of distribution and storage. In terms of the viability neither the BA3 nor the BA4 product has been compromised after twelve months of storage. However, storage at 4 ºC affected the stability and visual aspect of both CPA-8 formulations, mainly associated not only to the increase of RH but also a w. Moreover, it should be pointed out that flasks did not conserve refrigerated BA3 samples in a suitable way, since RH and a w increased noticeably making their visual properties unsightly after 10 months of cold storage. At that time, the BA4 products were better preserved at 4 ºC when packaged in flasks. Finally, this study also demonstrated that the most suitable packaging conditions for long-term storability (stored at 22 ºC) did not show any negative effect in the biocontrol efficacy of CPA-8 in nectarines artificially infected with M. fructicola and provide suitable product delivery and field application. In conclusion, these results contribute to the final stage of development of these two CPA-8 products, practically ready for registration, thus contributing to the environmental-friendly management of postharvest diseases in stone fruit.

Field validation of biocontrol strategies to control brown rot on stone fruit in several European countries

“…Both aforementioned BCAs have been studied extensively in relation to some of the major obstacles for their success as a commercial biocontrol product. These include the production of sufficient quantities of microorganisms to ensure optimum shelf life, 18 broadening the spectrum of action to a wider range of hosts, 11 and determining the responses to environmental stress under field conditions 19,20 . The results indicated that both BCAs are promising biocontrol products under commercial conditions.…”

Assessment of microbial biocontrol agent (BCA) viability to mechanical and thermal stress by simulating spray application conditions

“…The obtained information is essential when considering that not all BCAs can survive the conditions imposed during the formulation process at large‐scale production, even if in most cases protective substances are added to the formulation medium to improve the stability 32 . Additionally, the literature reported a strong effect of packaging (flasks versus bags) and storage conditions, especially temperature, on the shelf life of BCAs 33–36 . To exploit a BCA as a commercial product, important concentrations of microorganism biomass should be produced, stabilized, packaged and correctly stored/managed to be transported to its end‐user 32 .…”

“…32 Additionally, the literature reported a strong effect of packaging (flasks versus bags) and storage conditions, especially temperature, on the shelf life of BCAs. [33][34][35][36] To exploit a BCA as a commercial product, important concentrations of microorganism biomass should be produced, stabilized, packaged and correctly stored/managed to be transported to its end-user. 32 This is one of the reasons why their use is still limited and contains hurdles.…”

Partial Purification and Characterization of Antifungal Peptides Produced by Bacillus amyloliquefaciens PEP3 Against Phytophthora capsici

“…In addition, Bacillus species are also known to produce siderophore and volatile organic compounds (VOCs). VOCs are low molecular weight compounds that easily evaporates at normal temperature and pressure [17]. The effective components of VOCs varies between different strains.…”