Researchers dosed king oyster (Pleurotus eryngii) compost with a four-strain bacterial cocktail and saw biological efficiency (the yield you get per unit of substrate) jump to 89%, an 18% bump over uninoculated controls. The mushrooms also got more nutritious across the board, with higher protein, more total amino acids (up from 17.73 to 20.84 mg/g), and bigger stores of the functional compounds people prize mushrooms for, like β-glucan and trehalose. The standout finding for growers: the four-strain team consistently beat any single bacterium on its own, pointing to bacterial synergy as a cheap, low-input way to push both harvest size and quality.