NIR spectroscopy can provide information about the structural and physical properties of biological samples. Measurements of NIR trans-reflectance spectra in the 750-2500 nm range from suspended bacterial solutions reveal that there are specific absorption bands particularly at around 1440 nm. This band is mostly associated with water absorption and O-H bonds but by measuring trans-reflectance of liquid samples, the effects of water absorption can be reduced. This leads to a more effective bacterial detection and differentiation. The use of chemometrics also helps in discriminating and classifying bacterial species. NIR measurements of bacteria suspended in liquids provide a non-destructive method to identify microbes isolated from food.