by the United States government

“ If more than one person serves as trustee in the case, the aggregate compensation of such persons for such service may not exceed the maximum compensation prescribed for a single trustee by subsection (a) or (b) of this section, as the case may be. (d) The court may deny allowance of compensation for services or reimbursement of expenses of the trustee if the trustee failed to make diligent inquiry into facts that would permit denial of allowance under section 328 (c) of this title or, with knowledge of such facts, employed a professional person under section 327 of this title. ”