Soil degradation is a global problem and refers to the reduction or loss of the biological and economic productive capacity of the soil resource. In Europe, the countries most affected by soil degradation are undoubtedly those of the Mediterranean basin. Among these, Italy shows clear signs of degradation, with different characteristics, especially in the southern regions, where climatic and meteorological conditions strongly contribute to it. Apulia, the Tavoliere plain in particular, is a fragile and very sensitive ecosystem due to its intrinsic characteristics and the level of anthropic exploitation. Agricultural production pays the highest price, as increasing desertification due to climate change and the loss of agricultural land severely limit the extent of land available to produce food for an ever-growing population. Plant growth-promoting bacteria (PGPB) could be a low-cost and long-term solution to restore soil fertility, as they provide a wide range of benefits in agriculture, including increasing crop productivity, improving soil nutrient levels and inhibiting the growth of pathogens. This review shows how PGPB can be used to improve the quality of soils, their impact on agriculture, their tolerance to abiotic stresses (drought, salinity, heavy metals and organic pollutants) and their feasibility. The use of PGPB could be promoted as a green technology to be applied in marginal areas of Apulia to increase soil fertility, reduce pollution and mitigate the impacts of abiotic stresses and climate change. This is supported by a series of studies showing that the growth of plants inoculated with PGPB is superior to that of non-inoculated plants.

Fungal contamination represents a significant threat during peanut storage. In this research, a strain of Penicillium spp. was used as a test microorganism to assess its viability during peanut storage over 30 days at three different temperatures (4, 15, and 25 °C) and at two different inoculum levels (low-2 log CFU/g and high-5 log CFU/g). Two peanut types were tested: the Spanish type and the Virginia type. Independently of spore age, the fungus survived throughout the storage period, and in some samples (low inoculum Virginia-type peanuts) its level increased. In the second phase, four drying treatments, differing in temperature and duration, were tested. Fungal inactivation primarily depended on the temperature, while the duration of the drying process did not have a significant effect. At low temperatures, fungal inactivation was minimal and not statistically significant, suggesting that low-temperature treatments could pose a potential health risk.

Plant growth-promoting bacteria (PGPB) could exert positive effects on plant growth and productivity; however, little is known about the effects of variables during the production of PGPB biomass and how they could affect the performances of these microorganisms. This study investigated the effects of pH, temperature, and culture age on the growth of promising PGPBstrains, Bacillus sp. 36M and Stenotrophomonas sp. 20P, isolated from the rhizosphere of durum wheat. A fractional factorial 2^k design was applied to evaluate bacterial growth under varying conditions (pH 5.0–7.5; 15–35 °C; 24–72 h precultures). Multifactorial ANOVA revealed that all independent variables and their interactions significantly affected cell concentration (p < 0.05). Bacillus sp. 36M exhibited optimal growth when inoculated from 24 h cultures and incubated under moderate conditions (15 °C, pH 7.5), whereas Stenotrophomonas sp. 20P showed higher viability with 72 h cultures. These results demonstrate that the inoculum physiological state is a critical determinant of PGPB stress tolerance and should be specifically optimized for each strain. The greater technological robustness of Stenotrophomonas sp. 20P suggests its suitability for biofertilizer formulations requiring extended shelf-life or application under variable environmental conditions. In conclusion, this work provides a quantitative framework for tailoring PGPB production protocols to maximize field performance in sustainable agriculture.

To develop an enriched fermented milk, an experimental design was used in the first step by combining Lactiplantibacillus plantarum (isolated from oenological matrix) and Bifidobacterium animalis subsp. lactis strains, at different inoculum levels (4, 5 and 6 log CFU/mL) and temperatures (30, 35 and 40 °C) to study the effects on the acidification. Then, for the realization of the yoghurt-like drink, 5 log CFU/mL of both strains was inoculated in milk + 10% honey at 35 °C for 24 h; the fermented milk was stored at 4 °C for 50 days. The microbial concentrations were always >8 log CFU/mL.