A photo-bioreactor and method of operating are described. The photo-bioreactor includes a reactor vessel arranged to contain a fluid medium within which bio-material is grown, and at least one light-emitting rod extending into the reactor vessel, wherein the light-emitting rod has an elongate tubular member characterized by a length along a longitudinal axis and a width along an axis normal to the longitudinal axis, and designed with an outer wall that encloses one or more light-emitting devices arranged along the longitudinal axis, the outer wall being transparent to at least part of the light emitted by the one or more light-emitting devices into the reactor vessel. The photo-bioreactor further includes a drive system coupled to the elongate tubular member, and operatively configured to rotate the light-emitting rod about the longitudinal axis within reactor vessel, and circulate the fluid medium through the reactor.

Disclosed is a fermenter comprising one or more two phase injectors for providing oxygen for the fermentation and a circulation loop, circulating the fermentation broth and providing liquid for the two-phase injectors. Further disclosed is a fermentation plant comprising one or more fermenters of the invention and utility for the fermenters. Also disclosed is the use of the fermenters for the production of a fermentation product such as an enzyme.

The disclosure features methods that include obtaining a vibrational spectrum of a solution in a biological manufacturing system, analyzing the vibrational spectrum using a first chemometrics model to determine a value of a first quality attribute associated with the solution, analyzing the vibrational spectrum using a second chemometrics model to determine a value of a second quality attribute associated with the solution, and adjusting at least one parameter of a purification unit of the biological manufacturing system based on at least one of the values of the first and second quality attributes.