A major theme in the history of life is the formation of beneficial associations between symbiotic microbes and plants and animals (1). The pervasiveness of these associations in every ecosystem illustrates how the acquisition of a microbe's physiological capacity confers substantial fitness benefits to hosts (1). However, dependence on mutualistic microbes becomes a liability if antagonistic microbes attack or out-compete beneficial ones (2). Therefore, mechanisms to preserve beneficial microbes must be a widespread, although poorly understood, component of host-microbe mutualisms. Here, we show that a beetle uses a bacterium to protect its fungal food source from a competitor fungus.Southern pine beetles (SPB, Dendroctonus frontalis) engage in a beneficial symbiosis with the fungus Entomocorticium sp. A (EsA), which provides nourishment for their developing larvae. Adult SPBs carry EsA in a specialized storage compartment called a mycangium (Fig. 1A); excavate ovipositional galleries within the inner bark and phloem of host pine trees; and inoculate these galleries with EsA (3,4). The success of the SPB-EsA mutualism is challenged by an antagonistic fungus, Ophiostoma minus (Om), which can out-compete EsA and thereby disrupt SPB larval development (3,4). Our results indicate that successful maintenance of the SPB-EsA mutualism is likely mediated by an actinomycetous bacterium that produces antibiotics which selectively inhibit Om.The presence of previously unknown actinomycetes within the SPB-EsA mutualisms was established by scanning electron microscopy (SEM) and enrichment culture isolations. SEM revealed unexpected and profuse growth of actinomycetes within the galleries of SPBs, as well as inside the mycangia (Fig. 1B, Fig S1A). Isolations from 110 beetle individuals yielded 846 colony forming units (CFUs) of actinomycetes, including at least one CFU from each of 92 individuals. Out of 164 actinomycete CFUs selected to be transferred to pure culture, 99 isolates had a red morphotype while 65 isolates had a white morphotype. DNA sequence analyses confirmed the visual morphotype distinction, and within each of the two morphotypes there was complete 16S rDNA sequence identity. The two morphotypes form a monophyletic clade closely related toStreptomyces thermosacchari. We also successfully isolated the same red morphotype from 5 of 10 mycangia sampled.

Effects of microwave power output and sample mass on drying behavior, color parameters, rehydration characteristics and some sensory scores of thyme leaves were investigated. Within the range of the microwave power outputs, 180–900 W, and sample amounts, 25–100 g, moisture content of the leaves were reduced to 0.1 ± (0.01) from 4.05 kg water/kg dry base value. Drying times of the leaves were found to be varying between 3.5 and 15.5 min for constant sample amount, and 6.5 and 20.5 min for constant power output. Experimental drying data obtained were successfully modeled using artificial neural networks methodology. Statistical values of the test data were found to be 0.9999, 4.0937 and 0.025 for R‐square, MAPE (%) and RMSE, respectively. Some changes were recorded in the quality parameters, and acceptable sensory scores for the dried leaves were observed in all of the experimental conditions (P < 0.05). Practical Applications Drying is a very important preservation method used in the food industry. Microwave drying supplies uniform energy, higher drying rates and gives higher quality of the finished products compared with conventional drying methods. In order to model experimental drying data, many correlations that are available in literature may be used. However, artificial neural network methodology has become increasingly popular recently because of its capability of giving more general and precise results as also presented in this study.