Abstract: Described is an image forming apparatus, which makes it possible to create a vacant tray. The apparatus includes a paper sheet managing section to conduct consecutive operations including: acquiring the residual amount of the paper sheets accommodated in each of plurality paper sheet trays; calculating a total sum of residual amounts of paper sheets having the same attributes; comparing the above-calculated total sum with the maximum accommodating capacity of each of the paper sheet trays currently accommodating the paper sheets concerned; and notifying the operator of the fact that a vacant tray can be made by collecting the paper sheets concerned into a specific paper sheet tray, if there exists such paper sheets and a combination of paper sheet trays that make the total sum of the residual amounts of the paper sheets equal to or smaller than the maximum accommodating capacity of the specific paper sheet tray.

Abstract: There is provided is a method for producing lactic acid from glycerol, which comprises culturing a specific bacterium capable of producing lactic acid in a culture medium containing glycerol, or making cells of the bacterium, processed cells of the bacterium or immobilized product thereof contact with glycerol.

Abstract: Described is an image forming apparatus, which makes it possible to create a vacant tray. The apparatus includes a paper sheet managing section to conduct consecutive operations including: acquiring the residual amount of the paper sheets accommodated in each of plurality paper sheet trays; calculating a total sum of residual amounts of paper sheets having the same attributes; comparing the above-calculated total sum with the maximum accommodating capacity of each of the paper sheet trays currently accommodating the paper sheets concerned; and notifying the operator of the fact that a vacant tray can be made by collecting the paper sheets concerned into a specific paper sheet tray, if there exists such paper sheets and a combination of paper sheet trays that make the total sum of the residual amounts of the paper sheets equal to or smaller than the maximum accommodating capacity of the specific paper sheet tray.

Abstract: A printing system, comprises a plurality of image forming apparatuses connected to a network and including sheet trays and a detecting section provided to each sheet tray and to detect a capacity of empty space of each sheet tray; and a sheet managing section to obtain a capacity of empty space of each sheet tray of each image forming apparatus and to compare the capacity of empty space of each sheet tray with a capacity of one bundle of sheets as a unit of supply. In the case that the capacity of empty space of a sheet tray among the plural sheet trays of the plurality of image forming apparatuses is equal to or larger than the capacity of one plural bundle of sheets, the sheet managing section notifies that sheet supply can be conducted by one bundle of sheets as a unit of supply to the sheet tray.